US20050034302A1

US20050034302A1 - Component connecting apparatus and method and component mounting apparatus

Info

Publication number: US20050034302A1
Application number: US10/891,524
Authority: US
Inventors: Naoto Hosotani; Kazuki Fukada; Keiichi Iwata; Daido Komyoji
Original assignee: Individual
Current assignee: Panasonic Holdings Corp
Priority date: 2003-07-17
Filing date: 2004-07-15
Publication date: 2005-02-17
Also published as: US7357288B2; CN1578600B; CN1578600A

Abstract

When a component that has a connection portion to be connected to the electrode of a board and a weak heat-resistant portion of a lower heat-resisting property than the fusing point of a connection material for connecting the electrode of the board with the connection portion is connected to the board with interposition of the connection material between the electrode of the board and the connection portion, a cooling member is brought in contact with the weak heat-resistant portion or its neighborhood while heating the connection material by heating the board brought in contact with a placement member, and the quantity of heat conducted to the weak heat-resistant portion via the board is reduced by being conducted to the cooling member, carrying out the fusing of the connection material while preventing the occurrence of thermal damage to the weak heat-resistant portion.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a component connecting apparatus and method for connecting a component to a board by a heating device and a component mounting apparatus provided with the component connecting apparatus and relates, in particular, to a component connecting apparatus and method for connecting a small-sized low-profile component that partially has a weak heat-resistant portion of a low heat-resisting property to a board and a component mounting apparatus.
Regarding the conventional component mounting, an electronic component (a component) to be mounted on a circuit board (a board) has an electrode connection portion that is the portion to be connected to an electrode portion of the circuit board and a component body portion that carries the function of the electronic component. Regarding such the electronic component, mounting of the electronic component on the circuit board is carried out by forming and arranging a solder portion of solder or the like, which is a connecting material, between the electrode portion of the circuit board and the electrode connection portion of the electronic component, mounting the electronic component on the circuit board via the solder portion, thereafter heat-fusing the solder portion and subsequently cooling and solidifying the solder portion.
However, in general, the component body portion of the electronic component often has lower heat-resisting property than that of the electrode connection portion. If the heat in heat-fusing the solder portion is conducted also to the component body portion and the temperature of the component body portion becomes higher than its heatproof temperature, then the component body portion suffers thermal damage, and the electronic component is disadvantageously thermally damaged.
In order to prevent the occurrence of the aforementioned problem, with regard to the conventional component mounting, there have been invented apparatuses such that the temperature rise of the component body portion is restrained by removing the conducted heat by, for example, blowing cold blast against the component body portion and its neighborhood of the electronic component by a cold blast nozzle concurrently with blowing hot blast against the electrode connection portion and its neighborhood of the electronic component by a hot blast nozzle for the heat-fusing of the solder portion (refer to, for example, Japanese unexamined patent publication Nos. H10-51133, H6-151032, H9-283913 or 2002-16352).
Moreover, electronic components have conventionally been mounted on a flexible board (FPC (Flexible Printed Circuit Board)) in order to execute display control of an LCD section and carry out electrical connection between an LCD module and a mother board in the LCD module used for a mobile device or the like. A driver IC for the display control and chip components of capacitors and so on are mounted on this FPC. The connection portion of the driver IC has a narrow pitch, and the contamination of the connection portion becomes a cause for degrading the reliability of the LCD module. Therefore, the driver IC is mounted normally before the mounting of the chip components.
After the mounting of the driver IC, as shown in FIG. 28, solder is fed onto the FPC by a solder printer 501 that feeds solder to the FPC, and the chip component is placed on the FPC by a component mounter 502. Then, the resulting FPC is conveyed into a reflow apparatus 503 that has a heat source for fusing the solder, and the solder is fused to connect the chip component to the FPC. In this case, the circuit board can also be conveyed by a belt conveyer if its thickness is about 1 mm and has rigidity. However, in the case of a flexible film-shaped circuit board of, for example, the aforementioned FPC, as shown in FIG. 29, there is adopted a method for aligning and fixing FPC's 505 on a pallet 504 and conveying the FPC's 505 into the reflow apparatus 503. In this case, the reflow apparatus 503 is a reflow apparatus that heats atmosphere inside a furnace and carries out collective connection of the FPC's 505 on the pallet 504 with solder.
Moreover, when FPC's 505 of different types are produced, the FPC's 505 on which the components corresponding to the types are mounted are conveyed. In this case, the productivity is poor with the reflow apparatus that heats the atmosphere inside the furnace, and it is more efficient to heat only the required portions. Therefore, a reflow apparatus of local heating with a light beam system as shown in FIG. 30 is effective. In particular, to prevent light from being applied to the portions other than the required portions, it is effective to apply light emitted from a light emitting section 511 to the required portions through an opening 513 of a mask 512. It is to be noted that the reference numerals 506, 507 and 508 denote the chip component, IC and solder, respectively, in FIG. 30.
When FPC's 505 of the same type are mass-produced, the productivity is rather improved by arranging the FPC's 505 on a largest possible pallet 504 and carrying out connection with solder at a stroke. However, it has recently been often the case where there is insufficient time for the processes from the determination of the specifications of the circuit board to the production due to short product life, diversification of models, complication of design ascribed to advanced functions and flowability of market trend. Accordingly, it has become difficult to increase the production efficiency by the mass-production method with the large pallet 504.
Moreover, the production facility as shown in FIG. 28 is originally intended for processing large-size boards, and therefore, the apparatus itself is large. Particularly, the reflow apparatus, which heats the atmosphere inside the furnace, generally has a length of 3 to 5 m for soak heating. The equipment is extremely large with respect to the size of the circuit board that has a size of about 2 to 30 mm, and it is difficult to take flexible measures. It is to be noted that the system equipped with the solder printer 501, the component mounter 502 and the reflow apparatus 503 shown in FIG. 28 has a total length extended up to, for example, 7 m.
Moreover, although the light beam system is effective in the case of-same components and a small amount of components, it is a recent tendency that the amount and the types of chip components 506 on the FPC 505 are increasing in accordance with the functional advancement of the LCD module. When components of different light absorption coefficients exist on the FPC 505, the setting of the light application conditions and so on becomes difficult. For example, it is one method to control the conditions by the mask 512 for, for example, black electronic components and weak heat-resistant electronic components. However, there is a limitation in coping with each individual component only with the mask 512 because of the possible occurrence of a semi-fused state of adjacent solder.
On the other hand, in order to cope with the aforementioned problems, there has been invented a apparatus that carries out the heat-fusing of solder by providing a heating device for a stage on which the circuit board is placed instead of heating the atmosphere around the circuit board and heating the circuit board via the stage (refer to, for example, Japanese unexamined patent publication No. 2002-151553). In such the apparatus, the circuit board is directly heated instead of heating the atmosphere around the circuit board, and therefore, the energy necessary for the heating by the apparatus can be more efficiently used for the heat-fusing of the solder.

SUMMARY OF THE INVENTION

In the current situation in which the components to be mounted tend to be diversified into various types, functionally advanced and scaled down in size and thickness, it is sometimes the case where a specific material is employed in part of the component body portion in order to achieve the diversification into various types and advanced functions while allowing the heat-resisting property of the entire component body portion to be improved by the development and advancement of the materials for forming the electronic components, and the part is a weak heat-resistant portion that has a lower heat-resisting property. For example, there is an electronic component with a built-in CCD as the electronic component, and there is a color filter or the like as the weak heat-resistant portion arranged on the built-in CCD.
However, such the weak heat-resistant portion is sometimes arranged close to the electrode connection portion. In the above case, it is sometimes the case where the weak heat-resistant portion positioned close to the electrode connection portion to be heated cannot sufficiently be cooled by the conventional method although the component body portion can be roughly wholly cooled. In the above case, there is a problem that the weak heat-resistant portion disadvantageously suffers thermal damage and becomes unable to function as an electronic component. Moreover, such the problems tend to become significant as the electronic components are scaled down in its size and reduced in its thickness.
Accordingly, it is the real situation that, in mounting such the electronic component on the circuit board, the electronic component is mounted on the circuit board by manual soldering by an operator in order to prevent the thermal damage to the weak heat-resistant portion. It is a matter of course that efficient component mounting cannot be achieved by such means, and this leads to a problem that the automation of the operation is also difficult.
Furthermore, the diversification of circuit boards and electronic components to be mounted on the circuit boards are increasingly promoted. Particularly in the case of a circuit board of which the thickness tends to be reduced, the circuit board itself tends to cause warp, bend or the like. The aforementioned system, in which heat is conducted to the circuit board via the stage, has a problem that it is the case where the contact between the stage and the circuit board becomes insufficient and the heat conduction becomes insufficient, possibly causing the case where the heat-fusing of the solder cannot be achieved reliably and efficiently.
Accordingly, the object of the present invention is to solve the aforementioned problems and provide a component connecting apparatus and method and a component mounting apparatus, capable of reliably connecting a component to a circuit board and achieving high productivity by carrying out heat-fusing of a connection material when the component that has a connection portion to be connected to the electrode of the board and a weak heat-resistant portion of a lower heat-resisting property than the fusing point of the connection material for connecting the electrode of the board with the connection portion is connected to the board with interposition of the connection material between the electrode of the board and the connection portion, by carrying out the heat-fusing of the connection material while preventing the occurrence of thermal damage to the weak heat-resistant portion.
In order to achieve the aforementioned object, the present invention is constructed as follows.
According to a first aspect of the present invention, there is provided a component connecting apparatus comprising:
a placement member on which a board is placed, the board receiving thereon a component that has a connection portion to be connected to an electrode of the board and a weak heat-resistant portion (particularly the weak heat-resistant portion arranged in the neighborhood of the connection portion) of a heatproof temperature lower than a fusing point of a connection material for connecting the electrode of the board and the connection portion to each other with interposition of the connection material between the electrode of the board and the connection portion;
a heating device for fusing the connection material by heating the placement member to heat the board brought in contact with the placement member; and
a weak heat-resistant portion cooling device for cooling the weak heat-resistant portion or its neighborhood so as to prevent thermal damage to the weak heat-resistant portion by reducing a quantity of heat conducted from the heating device to the weak heat-resistant portion via the board (the placement member and the connection portion), whereby
the component is connected to the board which is placed on the placement member with interposition of the connection material by fusing the connection material by the heating device while carrying out the cooling by the weak heat-resistant portion cooling device and solidifying the fused connection material.
According to a second aspect of the present invention, there is provided the component connecting apparatus as defined in the first aspect, wherein the weak heat-resistant portion cooling device comprises a cooling member for carrying out the cooling by coming in contact with the weak heat-resistant portion or its neighborhood, thereby conducting the quantity of heat from the component.
According to a third aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the cooling by the cooling member is carried out so that a temperature of the weak heat-resistant portion becomes equal to or lower than its heatproof temperature when the connection material is fused by the heating device.
According to a fourth aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the weak heat-resistant portion is arranged inside the component, and the cooling member is brought in indirect contact with the weak heat-resistant portion via the neighborhood (external surface of the component) of the weak heat-resistant portion.
According to a fifth aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the cooling member is brought in indirect contact with the weak heat-resistant portion via the board.
According to a sixth aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the placement member has a placement surface which is brought in contact with a part of the board in a neighborhood of a position in which the electrode of the board is formed (i.e., in the position (region) of the other surface corresponding to the position (region) in which the electrode is formed on one surface of the board) and on which the board is placed.
According to a seventh aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, further comprising a suction device which is connected to the placement member and makes the placement member suck and hold the board.
According to an eighth aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the cooling member has a cooling fluid passage for making a cooling fluid pass through its inside, and the quantity of heat conducted from the component to the cooling member can be removed by making the cooling fluid pass through the cooling fluid passage.
According to a ninth aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the weak heat-resistant portion cooling device further comprises a cooling member moving unit for moving the cooling member between a position of contact of the cooling member and a position in which the contact can be released.
According to a tenth aspect of the present invention, there is provided the component connecting apparatus as defined in the ninth aspect, wherein the weak heat-resistant portion cooling device has the cooling member opposite to the placement member, and by positioning the cooling member in the position of contact by the cooling member moving unit, a position where the board is mounted is placed on the placement member is retained.
According to an eleventh aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, wherein the cooling member is formed of a material whose thermal conductivity is higher than thermal conductivity of a formation material of the component.
According to a twelfth aspect of the present invention, there is provided the component connecting apparatus as defined in the second aspect, further comprising a control unit for controlling a temperature of the placement member at a constant temperature by the heating device, and the control unit controls a heating temperature profile of the connection material and a temperature profile of the weak heat-resistant portion by controlling a time of contact between the placement member whose temperature is controlled at the constant temperature and the board and a time of contact between the cooling member and the component.
According to a thirteenth aspect of the present invention, there is provided the component connecting apparatus as defined in the first aspect, wherein the heating device has a heating member for heating the placement member, and
the component connecting apparatus further comprises a pressurizing unit for pressurizing the board against the heating member so as to make the board closely fit the placement member and make the placement member closely fit the heating member.
According to a fourteenth aspect of the present invention, there is provided the component connecting apparatus as defined in the thirteenth aspect, wherein the pressurizing unit comprises a plurality of protruding portions or configured portions, and the board is pressurized against the heating member via the protruding portions or the configured portions.
According to a fifteenth aspect of the present invention, there is provided a component mounting apparatus comprising:
a component placing apparatus for placing the component on the board with interposition of the connection material; and
the component connecting apparatus defined in the second aspect, for connecting the component which has been placed on the board by the component placing apparatus to the board.
According to a sixteenth aspect of the present invention, there is provided a component connecting method comprising:
placing a board on a placement member, the board receiving thereon a component that has a connection portion to be connected to an electrode of the board and a weak heat-resistant portion (particularly the weak heat-resistant portion arranged in the neighborhood of the connection portion) of a heatproof temperature lower than a fusing point of a connection material for connecting the electrode of the board and the connection portion to each other with interposition of the connection material between the electrode of the board and the connection portion;
bringing a cooling member in contact with the weak heat-resistant portion or its neighborhood while heating the connection material by heating the board brought in contact with the placement member, reducing a quantity of heat conducted to the weak heat-resistant portion via the board (the placement member and the connection portion) by conducting the quantity of heat to the cooling member and fusing the connection material while maintaining a temperature of the weak heat-resistant portion at or below its heatproof temperature; and
connecting the component to the board with interposition of the connection material by subsequently solidifying the connection material.
According to a seventeenth aspect of the present invention, there is provided the component connecting method as defined in the sixteenth aspect, wherein the weak heat-resistant portion is arranged inside the component, and the cooling member is brought in indirect contact with the weak heat-resistant portion via the neighborhood of the weak heat-resistant portion.
According to an eighteenth aspect of the present invention, there is provided the component connecting method as defined in the sixteenth aspect, wherein temperature rise in the weak heat-resistant portion is restrained so that the temperature of the weak heat-resistant portion becomes equal to or lower than the heatproof temperature by a time when a temperature of the connection material is maintained at a temperature not lower than its fusing point by heating of the board and the fusing of the connection material is completed.
According to a nineteenth aspect of the present invention, there is provided the component connecting method as defined in the sixteenth aspect, wherein the placement member is maintained at a constant heating temperature, and by controlling a time of contact between the placement member and the board and a time of contact between the cooling member and the component, a heating temperature profile of the connection material and a temperature profile of the weak heat-resistant portion are controlled.
According to a twentieth aspect of the present invention, there is provided the component connecting method as defined in the sixteenth aspect, wherein the board placed on the placement member is pressurized against the placement member to make the board closely fit the placement member, and the board is heated via the placement member.
Moreover, according to another aspect of the present invention, there is employed an electronic component connecting apparatus provided with a placement member that places thereon the circuit board on which the electronic component is mounted, a heating device that fuses the connection material for connecting the electronic component to the circuit board by heating the circuit board brought in contact with the placement member by heating the placement member by means of the heating member, and a pressurizing unit for pressurizing the placement member and the circuit board against the heating device.
Moreover, it is acceptable to employ an electronic component connecting apparatus, in which the pressurizing unit has protruding portions and makes the circuit board and the placement member closely fit the heating device by means of the protruding portions.
Moreover, it is acceptable to employ an electronic component connecting apparatus, in which the pressurizing unit has configured portions and makes the circuit board and the placement member closely fit the heating device by means of the configured portions.
Moreover, it is acceptable to employ an electronic component connecting apparatus, in which the pressurizing unit has protruding portions and configured portions and makes the circuit board and the placement member closely fit the heating device with interposition of an intermediate member.
It is further acceptable to employ an electronic component connecting apparatus in which the electronic component connecting apparatus is provided with a hot blast device.
It is also acceptable to use an electronic component connecting method characterized in that, by placing a circuit board on which an electronic component to be connected by a connection material on a placement member and depressing a connection material arrangement region on a placement member contact surface of the circuit board brought in contact with the placement member from an upper portion, the region corresponding to a region where the connection material is arranged on an electronic component placing surface of the circuit board on which the electronic component is placed, the heating of the circuit board in the connection material arrangement region by the contact is carried out while bringing the connection material arrangement region in contact with the placement member to fuse the connection material and connect the electronic component to the circuit board.
According to the first aspect of the present invention, placing the board, on which a component that has a connection portion for being connected to an electrode of the board and a weak heat-resistant portion of a heatproof temperature lower than a fusing point of a connection material is placed with interposition of the connection material, on a placement member and fusing the connection material by heating the placement member by the heating device and heating the board brought in contact with the placement member, the weak heat-resistant portion or its neighborhood can be cooled by the weak heat-resistant portion cooling device so as to prevent thermal damage to the weak heat-resistant portion by reducing the quantity of heat conducted to the weak heat-resistant portion by the heating. Therefore, the occurrence of thermal damage to the weak heat-resistant portion due to the heating can be prevented in advance while carrying out reliable fusing by the heating of the connection material.
For example, in the case where the weak heat-resistant portion is arranged close to the connection portion to such an extent that the quantity of heat conducted via the connection portion due to the heating of the connection material gives thermal damage to the weak heat-resistant portion by the heat-resisting property (i.e., the heat-resisting property that the heatproof temperature of the portion is lower than the fusing point of the connection material) of the weak heat-resistant portion in the component, the conventional reflow apparatus (component connecting apparatus) has had the disadvantage that, when the weak heat-resistant portion is cooled while heating the connection material, influence of the heating or cooling is disadvantageously exerted on the other due to the adjacent arrangement, and it has been difficult to make the reliable heat-fusing of the connection material compatible with the protection of the weak heat-resistant portion.
Even in the above case, by enabling the heat-fusing of the connection material arranged on the electrode of the board by heating the placement member by the heating device and thereby heating the board brought in contact with the heating device, the quantity of heat itself conducted to the main body of the component can be reduced according to the aforementioned first aspect. Moreover, the cooling by the weak heat-resistant portion cooling device can be carried out locally in the weak heat-resistant portion or its neighborhood. Therefore, the influence on the heating due to the cooling can be restrained to a minimum while enabling the reliable reduction in the quantity of heat conducted to the weak heat-resistant portion by the cooling. Therefore, it is possible to provide a component connecting apparatus capable of making the reliable heat-fusing of the connection material compatible with the protection of the weak heat-resistant portion.
According to the second aspect of the present invention, by virtue of the weak heat-resistant portion cooling device provided with the cooling member that conducts the quantity of heat from the component by coming in contact with the weak heat-resistant portion or its neighborhood, the local cooling of the weak heat-resistant portion can be achieved by bringing the cooling member in contact with the component. Moreover, by virtue of the heating and cooling both carried out by contact, the thermal influence exerted on the portions other than the contact portions can be further reduced. Therefore, even in the case of the mutually adjacent arrangement, the reliable heat-fusing of the connection material can be made reliably compatible with the protection of the weak heat-resistant portion.
According to the third aspect of the present invention, the cooling by the cooling member is carried out so that the temperature of the weak heat-resistant portion becomes equal to or lower than its heatproof temperature when the connection material is fused via the placement member and the board by the heating device. By this operation, the occurrence of thermal damage to the weak heat-resistant portion due to the heating can be prevented in advance.
According to the fourth aspect of the present invention, even in the case where the weak heat-resistant portion is arranged inside the component, by bringing the cooling member in indirect contact with the weak heat-resistant portion via the peripheral portion in the neighborhood of the weak heat-resistant portion, reliable local cooling of the weak heat-resistant portion can be achieved. Particularly, in the case where the weak heat-resistant portion is arranged inside the component without being exposed to the external surface of the component, it is sometimes difficult to reliably locally cool the weak heat-resistant portion arranged inside by merely blowing cold blast against the main body of the component as, for example, in the conventional case. In the above case, there is a problem that the possibility of the occurrence of thermal damage to the weak heat-resistant portion is increased, whereas the occurrence of such the problem can be solved by the third aspect.
According to the fifth aspect of the present invention, the reliable local cooling of the weak heat-resistant portion can be achieved not only in the case where the cooling member is brought in indirect contact with the weak heat-resistant portion via the external surface of the component but also in the case where the cooling member is brought in indirect contact with the weak heat-resistant portion via the board.
According to the sixth aspect of the present invention, the placement member has the placement surface on which the board is placed so as to be brought in partial contact with the board in the neighborhood of the position in which the electrodes are formed on the board, the board can be locally heated in the portions of contact between the placement surface and the board, and the quantity of heat in heating the board for the heat-fusing of the connection material can be made a necessary minimum. The quantity of heat conducted to the weak heat-resistant portion can be reduced while enabling the efficient heat-fusing.
According to the seventh aspect of the present invention, by further providing the suction device, which is connected to the placement member and sucks and holds the board on the placement member, the board placed on the placement member can be made to closely fit the placement member. Therefore, the thermal conductivity from the placement member to the board can be improved, allowing efficient heating to be achieved. This arrangement allows the time required for the heating for fusing the connection material to be reduced and allows the integrated quantity of the quantity of heat to the weak heat-resistant portion by the heating to be reduced, by which the occurrence of thermal damage to the weak heat-resistant portion can be more reliably prevented.
According to the eighth aspect of the present invention, the cooling member internally has the cooling fluid passage through the inside of which a cooling fluid can pass. With the arrangement that quantity of heat conducted from the component to the cooling member can be removed by making the cooling fluid pass through the cooling fluid passage, the cooling of the weak heat-resistant portion by the contact with the cooling member can be continually stably achieved.
According to the ninth aspect of the present invention, the weak heat-resistant portion cooling device is further provided with the cooling member moving unit that moves the cooling member between the position of the contact of the cooling member and the position in which the contact can be released, the cooling can be carried out in accordance with the necessity of the cooling.
According to the tenth aspect of the present invention, the weak heat-resistant, portion cooling device is provided with the cooling member opposite to the placement member. By positioning the cooling member in the position of the contact by the cooling member moving unit and retaining the placement position of the board on which the component is mounted on the placement member, the board can be made to closely fit the placement member, and the heating efficiency can be improved, allowing the time required for the heating to be reduced.
According to the eleventh aspect of the present invention, the cooling member is formed of a material that has a thermal conductivity higher than that of the formation material of the component. With this arrangement, the quantity of heat conducted to the weak heat-resistant portion or its neighborhood can be more efficiently conducted to the cooling member, and reliable efficient cooling can be achieved.
According to the twelfth aspect of the present invention, the temperature profile necessary for the heat-fusing of the connection material and the temperature profile for preventing the thermal damage to the weak heat-resistant portion can be achieved by controlling the time of contact between the board and the placement member and the time of contact between the cooling member and the component. Therefore, the prevention of the occurrence of thermal damage to the weak heat-resistant portion and the reliable fusing of the connection material can be compatibly achieved while allowing the construction of the control unit to be simple.
According to the thirteenth and fourteenth aspects of the present invention, the placement member and the heating device are provided, and the heating is carried out by the heating device by bringing the circuit board in contact with the placement member of approximately the same size as that of one circuit board. With this arrangement, the generation of loss in the case of a small-sized circuit board can be reduced, and heating corresponding to various types of circuit boards can be individually carried out. Therefore, circuit boards of diversified small-lot production can be manufactured with higher productivity than in the conventional case.
According to the fifteenth aspect of the present invention, there can be provided a component mounting apparatus capable of obtaining the effects of the aforementioned various aspects by adopting a construction integrated with the component placing apparatus.
According to the sixteenth aspect of the present invention, the board on which the component that has the connection portion for being connected to the electrode of the board and the weak heat-resistant portion of a heatproof temperature lower than the fusing point of the connection material is placed is put on the placement member, and the placement member is heated by the heating device to heat the board brought in contact with the placement member. By the above operation, the quantity of heat conducted to the weak heat-resistant portion by the heating can be reduced by being conducted to the cooling member with the cooling member brought in contact with the weak heat-resistant portion or its neighborhood while fusing the connection material. Moreover, since the temperature of the weak heat-resistant portion is maintained equal to or lower than its heatproof temperature by the conduction of the quantity of heat to the cooling member, there is no possibility of the occurrence of thermal damage to the weak heat-resistant portion. Accordingly, there can be provided a component connecting method capable of preventing in advance the occurrence of thermal damage to the weak heat-resistant portion due to the heating while carrying out reliable fusing by the heating of the connection material.
Moreover, according to another aspect of the present invention, temperature rise in the weak heat-resistant portion is restrained so that the temperature of the weak heat-resistant portion becomes equal to or lower than the heatproof temperature by the time when the temperature of the connection material is maintained at the temperature of not lower than the fusing point by the heating of the board and the fusing of the connection material is completed. With this arrangement, reliable fusing of the connection material can be carried out while reliably preventing the occurrence of thermal damage to the weak heat-resistant portion due to the heating.
Moreover, by virtue of the provision of the pressurizing unit for holding the circuit board on the placement member, the circuit board can closely fit the placement member, and the temperature control of the circuit board can be carried out with higher accuracy.
With the above arrangement, even when the circuit board is warped or bent, the entire connection material arrangement region can be reliably brought in contact with the heat conducting portion of the placement member regardless of the states of the regions other than the connection material arrangement region. Therefore, the connection of the electronic component to the circuit board can be achieved reliably and efficiently.
Moreover, in the case of a circuit board that has a thickness within a range of 0.02 mm to 1 mm or a circuit board constructed of a flexible board, the temperature response of the board to the heating control by the heating device is good, and therefore, heating can be carried out by temperature control appropriate for each type of circuit boards.
Moreover, an electronic component mounting apparatus provided with an electronic component connecting apparatus that can obtain the effects of the aforementioned aspects can be provided, and a method for connecting the electronic component to the circuit board capable of obtaining the effects of the aforementioned aspects can be provided.
Moreover, the mounting system can be a totally compacted mounting system. The system becomes a space-saving mounting system having high energy efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view showing the schematic construction of an electronic component connecting apparatus according to a first embodiment of the present invention;
FIG. 2 is a schematic sectional view showing the schematic construction of a component with a built-in CCD and an FPC that are connected together by the electronic component connecting apparatus of FIG. 1;
FIG. 3 is a schematic sectional view showing a state in which the connecting operation is carried out for the component with the built-in CCD and the FPC of FIG. 2;
FIG. 4 is a schematic perspective view showing the relation of arrangement among a stage, a heating device and a lower-side heatsink;
FIG. 5 is a schematic perspective view of an upper-side heatsink;
FIG. 6 is a schematic perspective view of an upper-side heatsink elevation unit;
FIGS. 7A, 7B, 7C, 7D and 7E are schematic explanatory views showing the procedure of the connecting operation of the component with the built-in CCD to the FPC in the electronic component connecting apparatus, in which FIG. 7A shows a state in which the FPC is fed to a place above the stage, FIG. 7B shows a state in which the FPC is placed on the stage, FIG. 7C shows a state in which the connecting operation of the component with the built-in CCD to the FPC is carried out, FIG. 7D shows a state in which the placement of the FPC on the stage is released and FIG. 7E shows a state in which a transport pallet is conveyed;
FIGS. 8A, 8B, 8C and 8D are schematic perspective views showing various forms of the upper-side heatsink, in which FIG. 8A shows a form that has a flat contact portion, FIG. 8B shows a form that has a roughly squared frame-like contact portion, FIG. 8C shows a form that has contact portions at four corners and FIG. 8D shows a modification example of the contact portions of FIG. 8C;
FIG. 9 is a schematic perspective view showing a cold blast passage formed through the upper-side heatsink;
FIG. 10 is a schematic sectional view showing the construction of a follower mechanism provided for the upper-side heatsink;
FIG. 11 is a schematic sectional view showing a state in which the connecting operation is carried out for the component with the built-in CCD and the FPC in an electronic component connecting apparatus according to a second embodiment of the present invention;
FIGS. 12A, 12B, 12C, 12D and 12E are schematic explanatory views showing the procedure of the connecting operation of the component with the built-in CCD to the FPC in the electronic component connecting apparatus, in which FIG. 12A shows a state in which the FPC is fed to a place above the stage, FIG. 12B shows a state in which the FPC is placed on the stage, FIG. 12C shows a state in which the connecting operation of the component with the built-in CCD to the FPC is carried out, FIG. 12D shows a state in which the placement of the FPC on the stage is released and FIG. 12E shows a state in which a transport pallet is conveyed;
FIG. 13 is a graph showing the temperature change states of a solder portion, a bonding portion and a color filter by a connection method according to an embodiment of the present invention;
FIG. 14 is a structural schematic explanatory view of the structure of an electronic component connecting apparatus according to a third embodiment of the present invention;
FIG. 15 is a perspective view of a circuit board suitable for heating by the electronic component connecting apparatus shown in FIG. 14;
FIG. 16 is a perspective view of a placement member provided for the electronic component connecting apparatus shown in FIG. 14;
FIG. 17 is a perspective view of a needle provided for the electronic component connecting apparatus shown in FIG. 14;
FIG. 18 is a graph showing one example of the temperature profile used for temperature control executed by the electronic component connecting apparatus shown in FIG. 14;
FIG. 19 is a graph showing another example of the temperature profile used for the temperature control executed by the electronic component connecting apparatus shown in FIG. 14;
FIG. 20 is a graph showing yet another example of the temperature profile used for the temperature control executed by the electronic component connecting apparatus shown in FIG. 14;
FIG. 21 is a perspective view showing a modification example of the electronic component connecting apparatus shown in FIG. 14;
FIG. 22 is a schematic view showing another modification example of the electronic component connecting apparatus shown in FIG. 14;
FIG. 23 is a view showing yet another modification example of the electronic component connecting apparatus shown in FIG. 14;
FIGS. 24A and 24B are views showing still other modification examples of the electronic component connecting apparatus shown in FIG. 1, wherein FIG. 24A shows a modification example in which the components are pressurized by a pressurizing member together with the board and FIG. 24B shows a modification example in which the components are pressurized by means of needles;
FIG. 25 is a schematic view showing a mounting system into which the electronic component connecting apparatus shown in FIG. 21 is incorporated;
FIG. 26 is a schematic view showing another mounting system into which the electronic component connecting apparatus shown in FIG. 21 is incorporated;
FIG. 27 is a schematic view showing yet another mounting system into which the electronic component connecting apparatus shown in FIG. 21 is incorporated;
FIG. 28 is a schematic view showing a conventional mounting system;
FIG. 29 is a schematic view showing conventional boards; and
FIG. 30 is a schematic view showing a conventional board heating method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.
The first embodiment of the present invention will be described in detail below with reference to the drawings.
(First Embodiment)
FIG. 1 shows a schematic external perspective view of an electronic component connecting apparatus 101 of one example of the component connecting apparatus according to the first embodiment of the present invention.
As shown in FIG. 1, the electronic component connecting apparatus 101 is an apparatus for connecting (i.e., mounting) a component, which is placed on the upper surface of a flexible circuit board (hereinafter referred to as an FPC (Flexible Printed Circuit Board)) 3 of one example of the board with interposition of a connection material, to the FPC 3 by heat-fusing (i.e., reflowing) the connection material. It is noted here that the term, “connecting,” means a mounting process that is carried out by fusing the connection material with heat and by thereafter solidifying the connection material and that makes it hard to release the resulting bonding state (i.e., connecting state) by applying external force to the component or the board. And in the bonding state the arrangement of the component and the board has been fixed. Before describing the concrete construction of this electronic component connecting apparatus 101, the structures of the FPC and the component handled by the above electronic component connecting apparatus 101 will be described below with reference to FIG. 2 that is a schematic sectional view of the FPC 3 on which the component is mounted.
(Structures of Component with Built-in CCD and FPC)
As shown in FIG. 2, a component 1 with a built-in CCD of one example of the electronic component that has a built-in CCD (Charge Coupled Device) 2 is mounted as the aforementioned component on the upper surface of the FPC 3. The component 1 with the built-in CCD is provided with a package section 4 that is a body with a bottom having a roughly rectangular parallelepiped external shape and a crystal cover section 5 that is a lid section that is mated with the opening located in an upper portion of the package section 4 and hermetically seals the internal space of the package section 4. A CCD 2 is arranged on internal bottom portion of the package section 4, and the arrangement of the CCD 2 is fixed by a bonding portion 6 formed of an adhesive material. A lower stepped portion 4 b and an upper stepped portion 4 c, which are two stepped portions, are formed along the inner peripheral surface inside the package section 4. A CCD electrode portion 7 electrically connected to the CCD 2 is formed on the lower stepped portion 4 b, and the CCD 2 and the CCD electrode portion 7 are electrically connected to each other via lead wires 8. The peripheral portion of the lower surface of the crystal cover section 5 is bonded to the upper surface of the upper stepped portion 4 c via bonding portions 9 formed of an adhesive material. A color filter 10 is arranged on the upper surface of the CCD 2. A space inside the package section 4 in which the CCD 2 is arranged requires airtightness because of the functional characteristics of the CCD 2 and the color filter 10. Therefore, an adhesive material having flexibility is used for the bonding portions 9 arranged between the upper stepped portion 4 c of the package section 4 and the crystal cover section 5.
A plurality of electrode connection portions 11 of one example of the connection portions connected to a plurality of electrode portions 3 a of one example of the electrodes formed on the FPC 3 are formed at the lower end portions of the package section 4. The arrangement of the electrode portions 3 a of the FPC 3 and the electrode connection portions 11 of the component 1 with the built-in CCD are determined so as to individually correspond to each other, and the component 1 with the built-in CCD is mounted on the upper surface of the FPC 3 via solder portions 12 of one example of the connection material arranged between the electrode connection portions 11 and the electrode portions 3 a. As shown in FIG. 2, in the above-mentioned mounting state, the bottom portion of the package section 4 closely fits the upper surface of the FPC 3. With this arrangement, the component 1 with the built-in CCD is supported roughly by the entire upper surface of the FPC 3, and the component 1 with the built-in CCD can be mounted on the FPC 3 in a stable state.
Moreover, in the present embodiment, the bonding portions 9 of the crystal cover section 5, the color filter 10 and the bonding portion 6 of the CCD 2 serve as examples of the weak heat-resistant portion of a lower heat-resisting property than that of the solder portions 12, the electrode connection portions 11 and the package section 14. For example, the heatproof temperature (condition) of the bonding portions 9 is not higher than 200° C., the heatproof temperature (condition) of the color filter 10 is not higher than 180° C., and the heatproof temperature (condition) of the bonding portion 6 is not higher than 180° C. The fusing point of the solder portion 12 is 206° C.
Moreover, in the component 1 with the built-in CCD, the weak heat-resistant portions of the bonding portions 9, the bonding portion 6 and the color filter 10 are arranged close to the electrode connection portions 11 to be bonded to the electrode portions 3 a of the FPC 3 via the respective solder portions 12. In this case, the expression of “arranged close to” means that the weak heat-resistant portions are arranged at a distance such that, as a consequence of the conduction of the quantity of heat for fusing the solder portions 12 also to the electrode connection portions 11 during the connection of the electrode connection portions 11 to the electrode portions 3 a with interposition of the solder portions 12, such the quantity of heat is conducted also to the weak heat-resistant portions, and the weak heat-resistant portions suffer thermal damage due to the conduction of the quantity of heat. The above-mentioned distance is influenced by the constituent materials of the portions located between the electrode connection portions 11 and each of the weak heat-resistant portions and the heating temperature of the solder portions 12.
The FPC 3 is a thin type film-shaped flexible board having flexibility. It is to be noted that the FPC 3 to be fed to the electronic component connecting apparatus 101 is in a state in which the component 1 with the built-in CCD has already been mounted on its surface. The mounting is carried out in, for example, an electronic component placing device that is installed adjacent to the electronic component connecting apparatus 101 or installed in another place.
(Construction of Electronic Component Connecting Apparatus)
As shown in FIG. 1, the electronic component connecting apparatus 101 is provided with a conveyance unit 14 for conveying a transport pallet 13, which is a support member for transporting three FPC's 3 that are combined as one set arranged on its upper surface, in a conveyance direction A that is rightward in the figure and a stage 16, which is one example of the placement member on the upper surface of which the FPC's 3 held by the transport pallet 13 conveyed to an approximate center position of the electronic component connecting apparatus 101 by the conveyance unit 14 are placed and on which the heating of the FPC's 3 is carried out. By placing each FPC 3 on this stage 16, the connection of the component 1 with the built-in CCD to the FPC 3-is carried out as described later. It is to be noted that the conveyance unit 14 is able to convey and feed the FPC 3 (each of the FPC's 3 held on the transport pallet 13) fed to the electronic component connecting apparatus 101 while making the FPC 3 to be placeable on the stage 16, convey the FPC 3 that has undergone the mounting operation on the stage 16 in the pallet conveyance direction A in a state in which the FPC 3 is still held on the transport pallet 13 and discharge the FPC from the electronic component connecting apparatus 101. The transport pallet 13 has opening portions 13 a that are formed slightly smaller than the external shape of the FPC 3 and individually correspond to the respective FPC's 3 held. For example, as shown in FIG. 2, the FPC's 3 can be held by supporting the end portions of the lower surfaces of the FPC's 3 by the end portions of the respective opening portions 13 a. That is, as shown in FIG. 2, each FPC 3 is exposed at the opening portion 13 a without being brought in contact with the transport pallet 13 except for the end portions on the lower surface side in a state in which the FPC is held on the transport pallet 13. It may be the converse case where the opening portion 13 a of the transport pallet 13 is formed larger than the external shape of the FPC 3 instead of the case where the opening portion 13 a is formed slightly smaller than the external shape of the FPC 3. However, in the above case, it is required to provide means (mechanism or the like) for securely holding the FPC 3 on the transport pallet 13.
A structure around the stage 16 on which the mounting operation (connecting operation, and this hereinafter holds same) of the component 1 with the built-in CCD on the FPC 3 in the electronic component connecting apparatus 101 is carried out will be described next with reference to the schematic sectional explanatory view shown in FIG. 3.
As shown in FIG. 3, the electronic component connecting apparatus 101 is provided with a stage 16 on which the aforementioned FPC 3 is placed and a heating device 18 that is installed in contact with the lower surface of this stage 16 and heats the FPC 3 brought in contact with the stage 16 by heating the stage 16.
The stage 16 concurrently has a function to place and hold the FPC 3 and a function to conduct heat to the FPC 3 and is easily replaceable with respect to the heating device 18 so as to be able to cope with various types of boards. Moreover, the stage 16 should preferably be made of a material of good thermal conductivity, such as aluminum, copper, magnesium, ceramic or the like. Particularly, when an aluminum material is used, the material is appropriate in terms of low cost and soaking property. In this case, the term of “soaking property” means the uniformity in the surface temperature distribution of an object in the contact portion when, for example, the quantity of heat is applied to the object by contact heat conduction. Moreover, as shown in the schematic perspective view of FIG. 4, the stage 16 has a roughly bracket-shaped planar configuration.
Moreover, as shown in FIGS. 3 and 4, a plurality of suction holes 20 for sucking the FPC 3 are opened at the placement surface 16 a that is the upper surface of the stage 16 with which the back surface of the FPC 3 is brought in contact. In the present embodiment, the placement surfaces 16 a of the stage 16 are arranged so as to correspond to the respective electrode portions 3 a of the placed FPC 3. It is to be noted that the number and the formation positions of the suction holes 20 can be determined in correspondence with the placed FPC 3.
The suction holes 20 are each formed so as to penetrate toward to the lower end portion of the stage 16, and the penetration portion is connected to a vacuum suction device (not shown) provided outside the stage 16. By operating the vacuum suction device, the FPC 3 can be sucked by the suction holes 20. Moreover, a pressure gauge (not shown) for measuring the suction pressure force is provided at the vacuum suction device or in a passage located between the vacuum suction device and the penetration portion, making it possible to confirm the suction pressure of the suction holes 20 controllingly or artificially, securing reliable suction operation.
The heating device 18 is constructed of, for example, a so-called ceramic heater, and the ceramic heater is arranged closely fitting the lower surface of the stage 16. Such the ceramic heater, which is allowed to have a control response characteristic of not longer than one second, is therefore able to cope with various temperature profiles. In the case of a so-called constant heating heater other than the ceramic heater, it takes several tens of seconds to several minutes for temperature rise and temperature fall, and the productivity is lowered in the use state in which the temperature rise and temperature fall are required. However, in a use state in which the temperature rise and temperature fall scarcely occur, i.e., in a use state in which the heater temperature is maintained constant, the heater can be used as a comparatively inexpensive heater.
The heating device 18 is further provided with a power supply and a temperature sensor (not shown), and it is possible to control the amount of current supplied from the power supply to the ceramic heater on the basis of the temperature detected by the temperature sensor and control the heating temperature to the desired temperature. The heating device 18 has a surface that is other than the surface brought in contact with the stage 16 and is covered with a heat insulating material (not shown). This arrangement makes it possible to restrain heat radiation from the surface other than the contact surface and efficiently conduct the heat of the heating device 18 to the stage 16.
Furthermore, as shown in FIG. 1, the electronic component connecting apparatus 101 is provided with a stage lifter 17 of one example of the placement member elevation unit for integrally driving the elevation operation of the stage 16 and the heating device 18 between the position (the contact position) in which each placement surface 16 a is brought in contact with the lower surface of the FPC 3 positioned above the stage 16 by the conveyance unit 14 and the position (the release position) in which the contact can be released. With this arrangement, the FPC 3 arranged above it can reliably be placed, and the FPC 3 can be discharged by being conveyed from above the stage 16 by the conveyance unit 14 while releasing the placement with the downward movement of the stage lifter.
As shown in FIGS. 3 and 4, the electronic component connecting apparatus 101 is further provided with a weak heat-resistant portion cooling device 22 for cooling the weak heat-resistant portions inside the component 1 with the built-in CCD. The weak heat-resistant portion cooling device 22 is provided with an upper-side heatsink 24 of one example of the cooling member capable of cooling the weak heat-resistant portion by heat conduction by coming in contact with the upper surface of the crystal cover section 5 that is the upper portion of the component 1 with the built-in CCD and a lower-side heatsink 26 of one example of the cooling member capable of cooling the weak heat-resistant portion by heat conduction by coming in contact with the placement portion of the component 1 with the built-in CCD on the FPC 3 from under the FPC 3.
As shown in FIGS. 3 and 5, the upper-side heatsink 24 has a configuration such that its end portions, which are located on the lower surface side and mutually opposed, are rectangularly raised, and the lower-side end surfaces of the rectangularly raised portions serve as contact portions 24 a to be brought in contact with the upper surface of the crystal cover section 5 of the component 1 with the built-in CCD. The external configuration on the lower side of the upper-side heatsink 24 is formed so as to have approximately the same size as that of the external shape of the crystal cover section 5, and the contact portions 24 a can be brought in contact with the respective mutually opposed end portions of the crystal cover section 5. With the upper-side heatsink 24 formed as described above, at least the four corner portions of the crystal cover section 5 that has an approximately rectangular planar shape are reliably brought in contact with any of the contact portions 24 a.
The reason why the upper-side heatsink 24 is formed as described above is that it is intended to reduce the quantity of heat caused by the heating by the heating device 18, the heat being conducted to the bonding portions 9 via the FPC 3, the solder portions 12, the electrode connection portions 11 and the package section 4, by conducting the quantity of heat to the contact portions 24 a via the crystal cover section 5 in the neighborhood of the bonding portions 9 in consideration of the fact that the bonding portions 9 arranged in the peripheral portion on the lower surface side of the crystal cover section 5 are weak heat-resistant portions. Moreover, the quantity of heat conducted to the bonding portions 9 has a characteristic that it is easily conducted so as to be concentrated on the bonding portions 9 arranged at the four corner portions of the crystal cover section 5 through experiments. Therefore, by bringing the contact portions 24 a in contact with the neighborhood of the bonding portions 9 at least in such the four corner portions, the temperature rise in the four corner portions can reliably be restrained. Moreover, in order to allow the above-mentioned function of the upper-side heatsink 24 to be efficiently achieved, the upper-side heatsink 24 is formed of a material of, for example, aluminum (thermal conductivity: 209 W/m·K) or the like, which has high thermal conductivity.
Moreover, as shown in the schematic explanatory view of FIG. 6, the weak heat-resistant portion cooling device 22 is provided with an upper-side heatsink elevation unit 28 of one example of the cooling member moving unit for driving the elevation operation of the upper-side heatsink 24 between the height position (the contact position) in which the upper-side heatsink 24 is brought in contact with the component 1 with the built-in CCD and the height position (the release position) in which the contact can be released. In this upper-side heatsink elevation unit 28, the upper-side heatsink 24 can employ, for example, an air cylinder with a rotation prevention function provided with a function to prevent the rotation roughly along the surface of the FPC 3 or the like.
Moreover, as shown in FIGS. 3 and 4, the lower-side heatsink 26 has a roughly rectangular-parallelepiped shape, and its upper surface serves as a contact portion 26 a to be brought in contact roughly with the center portion of the lower surface of the FPC 3 placed on the stage 16. Moreover, a suction hole 30, which has a function similar to that of the suction holes 20 of the stage 16, is formed at this contact surface 26 a, and the lower surface of the FPC 3 can be made to fit the contact surface 26 a by suction through this suction hole 30. It is to be noted that this suction hole 30 is connected to the aforementioned vacuum suction device (not shown).
The planar external shape of the contact surface 26 a of the lower-side heatsink 26 is made roughly the same as the planar external shape of the CCD 2, and the contact surface 26 a of the lower-side heatsink 26 can be brought in contact with the FPC 3 so as to correspond to the arrangement position of the CCD 2 in the component 1 with the built-in CCD.
The reason why the lower-side heatsink 26 is formed as described above is that it is intended to reduce the quantity of heat caused by the heating by the heating device 18, the heat being conducted to the bonding portion 6 and the color filter 10 via the FPC 3 and the package section 4, by conducting the quantity of heat to the contact portion 26 a via the FPC 3 in the neighborhood of the bonding portion 6 and the color filter 10 in consideration of the fact that the bonding portion 6 fixing the CCD 2 to the inner bottom portion 4 a of the package section 4 and the color filter 10 arranged on the upper surface of the CCD 2 are the weak heat-resistant portions. Moreover, the lower-side heatsink 26 is made to closely fit the lower surface of the FPC 3 by the suction of the suction hole 30, and therefore, the efficiency of heat conduction as described above can be improved to allow efficient heat conduction to be achieved. Therefore, the temperature rise in the bonding portion 6 and the color filter 10 can be restrained efficiently and reliably. Moreover, in order to allow the above-mentioned function of the lower-side heatsink 26 to be efficiently achieved, the lower-side heatsink 26 is formed of, for example, aluminum or the like, which has high thermal conductivity, similarly to the upper-side heatsink 24.
Moreover, as shown in FIG. 3, a plurality of cold blast passages 31 (one example of the cooling fluid passage), through which cooling air of one example of the cooling fluid can pass, are formed in the lower-side heatsink 26. These cold blast passages 31 are connected to a cold blast supply unit (not shown), and by supplying cold blast into the cold blast passages 31, the quantity of heat conducted to the lower-side heatsink 26 can be removed by the cold blast. Therefore, the quantity of heat can be removed by the cold blast even if the quantity of heat is conducted to the lower-side heatsink 26. Therefore, the temperature rise in the lower-side heatsink 26 can be restrained, and the heat conduction can be maintained in an efficient state.
As shown in FIG. 4, the weak heat-resistant portion cooling device 22 is further provided with a lower-side heatsink moving unit 32 of one example of the moving unit for driving the movement operation of the lower-side heatsink 26 between the position (the contact position) in which the approximate center portion of the lower surface of the FPC 3 is brought in contact with the lower-side heatsink 26 and the position (the release position), which is located on this side in the figure with respect to the contact position and in which the contact can be released away from the inside of the stage 16. By moving the lower-side heatsink 26 so as to be inserted in the stage 16 by this lower-side heatsink moving unit 32, the heatsink can be positioned in the position in which the contact can be released. By conversely moving the heatsink so as to move apart from the inside of the stage 16, the heatsink can be positioned in a position in which the influence of the heat of the stage 16 is not received. By being moved into the position located apart as described above, the quantity of heat, which has been conducted by contact with the FPC 3 and accumulated, can efficiently be radiated, so that the heatsink can be ready for heat conduction due to contact with the FPC 3 at the next time.
The lower-side heatsink 26 and the lower-side heatsink moving unit 32 as described above can be moved up and down by the stage lifter 17 together with the stage 16 and the heating device 18. The lower-side heatsink 26 positioned inside the stage 16 is to come in contact with the lower surface of the FPC 3 concurrently with the placement of the lower surface of the FPC 3 on the placement surfaces 16 a of the stage 16. That is, the placement surfaces 16 a of the stage 16 and the contact surfaces 26 a of the lower-side heatsink 26 are formed so as to be located at an approximately mutually equal height.
Moreover, as shown in FIG. 1, the electronic component connecting apparatus. 101 is provided with a control unit 90 that controls the operation of the aforementioned constituent members. This control unit 90 can carry out comprehensive control by interlinking the operations of conveyance operation of each transport pallet 13 by the conveyance unit 14, heating operation of the stage 16 by the heating device 18, elevation operation of the stage 16 and so on by the stage lifter 17, elevation operation of the upper-side heatsink 24 by the upper-side heatsink elevation unit 28, movement operation of the lower-side heatsink 26 and so on by the lower-side heatsink moving unit 32.
The control unit 90 has a function to control the heating temperature of the stage 16 by the heating device 18 on the basis of the data of the heating temperature profiles that have preparatorily been inputted and set. Further, the heat-fusing of the solder portions 12 conforming to the preset heating temperature profiles can be carried out by synthetically controlling the time of contact of each FPC 3 with the stage 16, the time of contact and the time of contact of the upper-side heatsink 24 with the component 1 with the built-in CCD, the time of contact of the lower-side heatsink 26 with the FPC 3 and so forth on the basis of the data of the heating temperature profiles as described above.
(Component Connecting Operation)
Concrete operation for mounting the component 1 with the built-in CCD on the FPC 3 by heat-fusing the solder portions 12 on the FPC 3 on which the component 1 with the built-in CCD is mounted and thereafter cooling and solidifying the solder portions 12 in the electronic component connecting apparatus 101 that has the aforementioned construction and functions will be described next with reference to the schematic explanatory views shown in FIGS. 7A through 7E. It is to be noted that the operations subsequently described are carried out by comprehensively controlling the operations described later by the control unit 90 of the electronic component connecting apparatus 101 while interlinking the operations.
As shown in FIG. 7A, three FPC's 3 are held on the transport pallet 13, and the transport pallet 13 is conveyed along the pallet conveyance direction A by the conveyance unit 14. The conveyance is stopped in a state in which one FPC 3 (the FPC 3 located at the right end in the figure) out of the FPC's 3 is positioned above the stage 16. Subsequently, the transport pallet 13 is fixed in the position by a position regulating pin 15 a and stoppers 15 b. It is to be noted that the stage 16 is put in a state in which it is preheated to a prescribed temperature by the heating device 18 and retained. Concurrently with the operation, the lower-side heatsink 26 positioned in a position apart from the stage 16 by the lower-side heatsink moving unit 32 is moved so as to be inserted into the stage 16.
Subsequently, as shown in FIG. 7B, the heating device 18 and the lower-side heatsink 26 are integrally moved up together with the stage 16 by the stage lifter 17, and the placement surfaces 16 a of the stage 16 and the contact portion 26 a of the lower-side heatsink 26 are brought in contact with the lower surface of the FPC 3. Moreover, suction of the lower surface of the FPC 3 is carried out by the suction holes 20 and 30 concurrently with this contact. Concurrently with the operation, the upper-side heatsink 24 positioned in the release position is moved down to the contact position by the upper-side heatsink elevation unit 28, and its contact portions 24 a are brought in contact with the upper surface of the crystal cover section 5 of the component 1 with the built-in CCD. It may be the case where FPC pressurizing members 16 b that pressurize and hold the upper surface end portions of the FPC 3 are moved down in synchronization with the upward movement of the stage 16 by the stage lifter 17 as shown in FIG. 7B. In the above-mentioned case, there is an advantage that the FPC 3, which is a film-shaped board having flexibility, can be held more reliably than when the FPC is held on the stage 16 by suction from the lower surface side.
As shown in FIG. 7C, the quantity of heat is conducted from the stage 16 heated by the heating device 18 to the solder portions 12 via the FPC 3 by the contact between the placement surface 16 a of the stage 16 and the FPC 3, starting the heating of the solder portions 12. At this time, the elevated temperature of the solder portions 12 is controlled by setting the heating temperature of the stage 16 by the heating device 18 to the preset specified temperature and controlling the time of contact between the placement surface 16 a of the stage 16 and the FPC 3 (i.e., controlling the time from the start of contact to the release of the contact).
On the other hand, the quantity of heat conducted for heating to the solder portions 12 via the FPC 3 is conducted also to the bonding portions 6 and 9 and the color filter 10 inside the component 1 with the built-in CCD. However, due to the contact between the contact portions 24 a of the upper-side heatsink 24 and the end portions of the crystal cover section 5, the quantity of heat conducted to the bonding portions 9 is partially or almost totally conducted to the contact portions 24 a via the crystal cover section 5. Likewise, due to the contact between the contact portions 26 a of the lower-side heatsink 26 and the lower surface of the FPC 3, the quantity of heat conducted to-the bonding portion 6 and the color filter 10 is partially or almost totally conducted to the contact portions 26 a through the neighborhood of the inner bottom portion 4 a of the package section 4. By virtue of the fact that the quantity of heat conducted as described above is partially or almost totally conducted to the upper-side heatsink 24 or the lower-side heatsink 26, the temperature rise in the bonding portion 6, the bonding portions 9 and the color filter 10 can be restrained.
Subsequently, as shown in FIG. 7D, the solder portions 12 are raised in temperature up to its fusing point of, for example, a temperature of not lower than 215° C., maintained for a preset specified time at the temperature. Thereafter, the stage 16, the lower-side heatsink 26 and the heating device 18 are integrally moved down by the stage lifter 17 to release the contact between the stage 16 and the lower-side heatsink 26 and the FPC 3. The FPC pressurizing members 16 b are also moved up in accordance with this downward movement operation, releasing the holding of the FPC 3 on the stage 16. Further, the upper-side heatsink 24 is moved up by the upper-side heatsink elevation unit 28 concurrently with these operations, releasing the contact between the upper-side heatsink 24 and the crystal cover section 5.
Further, the lower-side heatsink 26 is subsequently moved to the position in which the heatsink is separated from the inside of the stage 16 by the lower-side heatsink moving unit 32, radiating the quantity of heat that has been conducted to and accumulated in the lower-side heatsink 26 for the next operation. Instead of the case where the movement of the lower-side heatsink 26 to the position of release by the lower-side heatsink moving unit 32 as described above, it may be a case where the movement is not carried out. The necessity of such the movement can be determined on the basis of the cooling ability of each cold blast passage 30 formed in the lower-side heatsink 26, a stand-by time until the heating of the next FPC 3 and so on. It is to be noted that the heating temperature of the heating device 18 is made to remain maintained at the aforementioned constant temperature so as to be readily copable with the heating of the next FPC 3.
Subsequently, as shown in FIG. 7E, the positioning pin 15 a and the stopper 15 b, which are positioning the transport pallet 13, are moved down to release the positioning. After the release, the transport pallet 13 is conveyed along the pallet conveyance direction A by the conveyance unit 14 so that the next FPC 3 arranged adjacent be positioned above the stage 16.
Although the case where the heating temperature of the heating device 18 is maintained constant according to the description of the aforementioned operation procedure, the present invention is not limited to such the case. Instead of the above case, it may be, for example, a case where the heating temperature of the stage 16 by the heating device 18 is raised according to a preset condition while the stage 16 and the FPC 3 are put in contact with each other. Moreover, it may be, for example, a case where the heating temperature of the stage 16 by the heating device 18 is lowered after the release of the contact between the stage 16 and the FPC 3. In the above case, only necessary heating can be carried out when it is needed, and therefore, the power consumption of the heating device 18 can be reduced. In this case, the heating temperature of the heating device 18 is raised again on the basis of a specified condition by the time when the next FPC 3 is moved to and placed in the place above the stage 16.
As described above, the configuration of the upper-side heatsink 24 is not limited to the configuration as shown in FIG. 5, and various configurations can be adopted. For example, as shown in FIG. 8A, it is acceptable to adopt a form such that the contact portion 24 a is formed so as to closely fit the entire upper surface of the crystal cover section 5 of the component 1 with the built-in CCD by forming the lower surface of the upper-side heatsink 24 into a flat state. In the case of such the form, the production and processing of the upper-side heatsink 24 can be made simple.
Moreover, as shown in FIG. 8B, it may be a case where the contact portion 24 a of the upper-side heatsink 24 is formed into a roughly squared frame-like configuration. In the above case, the contact portion 24 a can be brought in contact with only the neighborhood of the bonding portions 9 from which the quantity of heat is required to be removed. Therefore, the quantity of heat can be made to effectively escape by heat conduction, and the cooling of the bonding portions 9 can be carried out.
Moreover, it may be a case where the contact portions 24 a are formed at the four corner portions of the lower surface of the upper-side heatsink 24 as shown in FIG. 8C. In the above case, the contact portions 24 a can be brought in contact with the neighborhood of the four corner portions of the bonding portions 9 where the temperature can be comparatively easily raised as described above, and therefore, cooling by more effective heat conduction can be carried out. It is to be noted that the contact portions 24 a are each formed so as to have, for example, an approximately square plane and so that its one side dimension d becomes approximately one third of the dimension of one side of the lower surface plane of the upper-side heatsink 24.
Moreover, as shown in FIG. 8D, it is also possible to provide a form of a combination of the form of FIG. 5 and the form of FIG. 8C.
Instead of the case where the formation material of the contact portions 24 a that have a rectangularly projected shape of the upper-side heatsink 24 and the formation material of the main body of the upper-side heatsink 24 are formed of a mutually identical material, it may be a case where they are formed of mutually different materials. In the above case, the heat conduction from the crystal cover section 5 can be improved by using a material of higher thermal conductivity for the contact portion 24 a. Such the material of high thermal conductivity is often a comparatively expensive material. However, in such the case, the material is used for only the contact portions 24 a, and therefore, an increase in the production cost of the upper-side heatsink 24 can be restrained. When the contact portions 24 a are formed of the different material, the contact portions 24 a can be formed by being bonded to the lower surface of the upper-side heatsink 24 by brazing or in a similar manner.
Moreover, as shown in FIG. 9, it may be a case where a cold blast passage 34 (one example of the cooling fluid passage) similar to the cold blast passages 31 formed in the lower-side heatsink 26 is formed inside the upper-side heatsink 24. For example, a cold blast inlet port 34 a is formed at the illustrated upper surface of the upper-side heatsink 24, cold blast outlet ports 34 b are formed on the illustrated side surfaces, and the cold blast passage 34 is formed so that the cold blast inlet port 34 a communicates with the cold blast outlet ports 34 b. Further, it is possible to connect a cold blast supply unit (not shown) to the cold blast inlet port 34 a, make the supplied cold blast pass through the inside of the cold blast passage 34 to remove the quantity of heat accumulated in the upper-side heatsink 24 by this passage and discharge the cold blast from the cold blast outlet ports 34 b. At this time, since the cold blast outlet ports 34 b are provided on the side surfaces of the upper-side heatsink 24, the discharged cold blast neither blows toward the component 1 with the built-in CCD nor hinder the heat-fusing of the solder portions 12.
Moreover, it may be a case where a follower mechanism is provided for the upper-side heatsink 24 as shown in FIG. 10. In the above case, impact at the time of contact can be alleviated in bringing the contact surface 24 a of the upper-side heatsink 24 in contact with the crystal cover section 5 of the component 1 with the built-in CCD that is a precision component. If the contact surface 24 a and the upper surface of the crystal cover section 5 are not completely parallel to each other and slightly inclined, they can be made to closely fit each other so as to adjust the contact surface 24 a side with respect to the crystal cover section 5, and efficient heat conduction can be achieved.
In concrete, as shown in FIG. 10, the upper-side heatsink 24 is provided with a guide section 38 that has a support portion 38 a for supporting the upper-side heatsink 24 and slidably guides the upper-side heatsink 24 in the vertical direction along its inner surface, a spring section 40 that is one example of the elastic body provided on the upper surface of the upper-side heatsink 24 and an urging member 36 that consistently urges the upper-side heatsink 24 toward the lower side via the spring section 40. With this construction, even if the contact surface 24 a of the upper-side heatsink 24 and the crystal cover section 5 are brought in contact with each other, the impact of the upper-side heatsink 24 can be alleviated by the spring section 40 that serves as a buffer member. Moreover, the contact surface 24 a can freely be inclined at a small angle. As shown in FIG. 10, it may be a case where a cooling passage 36 a is provided inside the urging member 36 and the upper-side heatsink 24 is cooled. Moreover, it may be a case where a rubber-based material of a shock absorbing rubber or the like is employed instead of the case where the spring section 40 is employed as the elastic body.
Moreover, as another effect of providing the aforementioned follower mechanism, there is, for example, an effect that a force of mutual contact (pressurization force) between the contact surfaces 24 a and the crystal cover section 5 can be approximately uniformed when the upper-side heatsink 24 has a plurality of contact surfaces 24 a on its lower surface. Therefore, in the above case, the state of heat conduction in the portions can be approximately uniformed, and satisfactory heat conduction can be achieved.
Although the present first embodiment has been described on the basis of the arrangement that the weak heat-resistant portion cooling device 22 is provided with the upper-side heatsink 24 and the lower-side heatsink 26, the present embodiment is not limited to the case. It may be a case where either one of the upper-side heatsink 24 and the lower-side heatsink 26 is provided. For example, when the quantity of heat conducted to the bonding portion 6 and the color filter 10 can be removed by the cooling by means of only the upper-side heatsink 24, the necessity for providing the lower-side heatsink 26 can be eliminated. Moreover, the converse case is possible. Otherwise, it can also be selectively determined whether or not each of the heatsinks is necessary depending on the heat-resisting properties of the materials used for the bonding portion 6, the bonding portions 9 and the color filter 10.
Moreover, the present first embodiment has been described on the basis of the arrangement that the electrode connection portions 11 are formed so that the entire lower surface of the package section 4 closely fits the upper surface of the FPC 3 in the state in which the electrode connection portions 11 formed on the lower surface of the component 1 with the built-in CCD are bonded via the electrode portions 3 a formed on the upper surface of the FPC 3 and the solder portions 12. However, the form of the electrode connection portions 11 is not limited only to the above case. Instead of the above case, it may be, for example, a case where the electrode connection portions 11 of the component 1 with the built-in CCD are lead wires, and the lead wires are connected to the electrode portions 3 a via the solder portions 12. Such the lead wires are projecting from the lower surface of the package section 4. Therefore, a gap is generated between the lower surface of the package section 4 and the upper surface of the FPC 3 in the above-mentioned connected state, and this makes it possible to reduce the quantity of heat conducted to the bonding portion 6 and the color filter 10 by virtue of the provision of the gap.
Moreover, by positioning the upper-side heatsink 24 in the height position of contact with the component 1 with the built-in CCD by the upper-side heatsink elevation unit 28, the placement position of the FPC 3, on which the component 1 with the built-in CCD is mounted, on the stage 16 can be retained. Using the above function can obviate the need for, for example, the suction function of the stage 16.
Moreover, instead of the case where the electronic component connecting apparatus 101 that has the aforementioned functions and construction is constructed as a single apparatus, it may be a case where the electronic component mounting apparatus is constituted by integrating the apparatus with, for example, an electronic component placing apparatus that is one example of the component placing apparatus for placing the component 1 with the built-in CCD on the FPC 3 into one apparatus.
According to the first embodiment, the following various effects can be obtained.
First of all, instead of the arrangement that the stage 16 on which the FPC 3 is placed for heating supports the entire lower surface of the FPC 3 in the electronic component connecting apparatus 101, the placement surfaces 16 a can be provided partially in correspondence with the arrangement positions of the solder portions 12 required to undergo heat-fusing. With this arrangement, local heating of only the required portions can be carried out via the placement surfaces 16 a of the stage 16 by the heating device 18. Therefore, effective heating of the solder portions 12 can be achieved, and the quantity of heat conducted to the components for which the heating is not required or, for example, the weak heat-resistant portions of the bonding portion 6, the bonding portions 9 and the color filter 10 can be reduced, making it possible to reduce the possibly of the occurrence of thermal damage to the weak heat-resistant portions.
Moreover, by virtue of the provision of the suction holes 20 at the placement surfaces 16 a of the stage 16, the lower surface of the FPC 3 placed on the stage 16 can be sucked by the suction holes 20, and the FPC 3 can be made to closely fit the placement surfaces 16 a. Therefore, the efficiency of heat conduction from the placement surfaces 16 a to the FPC 3 can be improved, and efficient heating can be carried out.
Moreover, when the solder portions 12 are heated in the aforementioned system, the quantity of heat conducted to the solder portions 12 is partially conducted to the weak heat-resistant portions of the bonding portion 6, the bonding portions 9 and the color filter 10 through the FPC 3, the electrode connection portions 11, the package section 4 and so on. However, by virtue of the arrangement that the contact surfaces 24 a of the upper-side heatsink 24 are brought in contact with the upper surface of the crystal cover section 5 and the contact surface 26 a of the lower-side heatsink 26 is brought in contact with the lower surface of the FPC 3, the quantity of heat conducted can be conducted so as to escape to the heatsinks. Therefore, the temperature rise in the weak heat-resistant portions during the heating of the solder portions 12 can be restrained, and the occurrence of thermal damage due to the temperature rise in the weak heat-resistant portions can be restrained. Therefore, components that internally have weak heat-resistant portions like the component 1 with the built-in CCD can reliably be mounted on the FPC 3 while preventing the occurrence of thermal damage to the weak heat-resistant portions.
Moreover, the contact surfaces 24 a of the upper-side heatsink 24 are arranged so as to be able to come in contact with at least the four corner portions of the crystal cover section 5, the quantity of heat, which is conducted to the bonding portions 9 that connect the four corner portions at which the temperature is easily raised by the conduction of the quantity of heat, is allowed to escape more effectively to the upper-side heatsink 24. Therefore, the occurrence of thermal damage to the bonding portions 9 can reliably be prevented.
Moreover, the configuration and arrangement of the contact surfaces 26 a of the lower-side heatsink 26 are made to correspond approximately to the configuration and arrangement of the CCD 2 with respect to the package section 4 in the component 1 with the built-in CCD. With this arrangement, the quantity of heat conducted to the bonding portion 6 that connects the CCD 2 to the inner bottom portion 4 a of the package section 4 and the color filter 10 is allowed to escape more effectively to the lower-side heatsink 26. Therefore, the occurrence of thermal damage to the bonding portion 6 and the color filter 10 can reliably be prevented.
Moreover, by virtue of the arrangement that the upper-side heatsink 24 and the lower-side heatsink 26 are locally brought in contact with the neighborhood of the weak heat-resistant portions in the component 1 with the built-in CCD, no influence is exerted on the heating of the solder portions 12 that require reliable heating even if the quantity of heat is conducted to the heatsinks so as to escape and the contact portions and their neighborhoods are cooled. Therefore, the local heating of the required portions and the local cooling of the required portions can be made compatible.
(Second Embodiment)
The present invention is not limited to the aforementioned embodiment but allowed to be embodied in various forms. For example, the electronic component connecting apparatus of the second embodiment of the present invention is provided with a weak heat-resistant portion cooling device 122 of a construction different from that of the electronic component connecting apparatus 101 of the first embodiment. FIG. 11 shows a schematic sectional view showing the schematic construction of this weak heat-resistant portion cooling device 122. In the following description, the portions having constructions similar to those of the first embodiment are denoted by same reference numerals for the sake of easy understanding of the description.
As shown in FIG. 11, the weak heat-resistant portion cooling device 122 is provided with a cold blast supply nozzle 124 capable of blowing cold blast from above the component 1 with the built-in CCD in place of the upper-side heatsink 24 although it is provided with a lower-side heatsink 26 similarly to the weak heat-resistant portion cooling device 22 of the first embodiment.
The above-mentioned cold blast supply nozzle 124 is able to blow cold blast against principally the upper surface of the crystal cover section 5 of the component 1 with the built-in CCD and able to blow cold blast against particularly at least the four corner portions of the crystal cover section 5. The cold blast supply nozzle 124 has its formation width formed so as to be smaller than the formation width of the component 1 with the built-in CCD. This arrangement is to prevent the cold blast supplied from the cold blast supply nozzle 124 from being blown directly toward the solder portions 12, so that the heat-fusing of the solder portions 12 is not hindered. It is to be noted that the arrangement of the cold blast supply nozzle 124 is not limited to the above-mentioned arrangement so long as the blowing of the cold blast directly toward the solder portions 12 is prevented.
As described above, the cold blast supplied from the cold blast supply nozzle 124 is blown against the crystal cover section 5, by which the quantity of heat conducted to the bonding portions 9 can be removed from the surface of the crystal cover section 5 by means of the cold blast, and the temperature rise in the bonding portions 9 can be restrained.
It is to be noted that control of the supply operation of the cold blast by the cold blast supply nozzle 124 is executed as comprehensive control by the control unit 90 while being interlinked to the other operations.
The procedure of the mounting operation of the component 1 with the built-in CCD onto the FPC 3 carried out in the electronic component connecting apparatus that has the aforementioned construction will be described in concrete with reference to the schematic explanatory views shown in FIGS. 12A through 12E. It is to be noted that the operations described hereinafter are executed under comprehensive control of the control unit 90 while being interlinked to one another.
As shown in FIG. 12A, three FPC's 3 are held on the transport pallet 13, and the transport pallet 13 is conveyed in the pallet conveyance direction A (leftward direction in the figure) by the conveyance unit 14. In a state in which one FPC 3 (the FPC 3 located at the left end in the figure) of the FPC's 3 is positioned above the stage 16, the conveyance is stopped. Subsequently, the transport pallet 13 is fixed in the position by the position regulating pins 15 a and the stopper 15 b. It is to be noted that the stage 16 has been heated to and maintained at a preset temperature by the heating device 18. Concurrently with the operation, the lower-side heatsink 26 positioned in a position separated from the stage 16 by the lower-side heatsink moving unit 32 is moved so as to be inserted into the stage 16.
Subsequently, as shown in FIG. 12B, the heating device 18 and the lower-side heatsink 26 are integrally moved up together with the stage 16 by the stage lifter 17, so that the placement surfaces 16 a of the stage 16 and the contact portion 26 a of the lower-side heatsink 26 are brought in contact with the lower surface of the FPC 3. Upon achieving this contact, suction of the lower surface of the FPC 3 is carried out by the suction holes 20 and 30. Concurrently with this operation, supply of cold blast from the cold blast supply nozzle 124 toward the upper surface of the component 1 with the built-in CCD is started. It may be a case where FPC pressurizing members 16 b that pressurize and hold the upper end portions of the FPC 3 are moved down in synchronization with the upward movement of the stage 16 by the stage lifter 17 as shown in FIG. 12B.
As shown in FIG. 12C, the quantity of heat is conducted from the stage 16 heated by the heating device 18 to the solder portions 12 via the FPC 3 due to the contact between the placement surfaces 16 a of the stage 16 and the FPC 3, starting the heating of the solder portions 12. At this time, the heating temperature of the stage 16 by the heating device 18 is made constant at the preset temperature, and control of the elevated temperature of the solder portions 12 is executed by controlling the time of contact between the placement surfaces 16 a of the stage 16 and the FPC 3.
On the other hand, the quantity of heat conducted for heating to the solder portions 12 via the FPC 3 is conducted also to the bonding portions 6 and 9 and the color filter 10 inside the component 1 with the built-in CCD. However, the quantity of heat conducted to the bonding portions 9 is partially or almost totally removed by the cold blast blown via the crystal cover section 5 by the blowing of cold blast from the cold blast supply nozzle 124. Moreover, due to the contact between the contact portions 26 a of the lower-side heatsink 26 and the lower surface of the FPC 3, the quantity of heat conducted to the bonding portions 6 and the color filter 10 is partially or almost totally conducted to the contact portions 26 a via the neighborhood of the inner bottom portion 4 a of the package section 4. By thus allowing the quantity of heat conducted partially or almost totally as described above to be cooled by the cold blast blown or heat conduction to the lower-side heatsink 26, the temperature rise in the bonding portion 6, the bonding portions 9 and the color filter 10 can be restrained.
Subsequently, as shown in FIG. 12D, the temperature of the solder portions 12 is raised up to its fusing point of, for example, not lower than 215° C. and maintained at the temperature for a preset specified time. Thereafter, the stage 16, the lower-side heatsink 26 and the heating device 18 are integrally moved down by the stage lifter 17, releasing the contact between the stage 16 and the lower-side heatsink 26 and the FPC 3. Moreover, the FPC pressurizing members 16 b are also moved up with this downward movement operation, releasing the holding of the FPC 3 on the stage 16. Further, the supply of cold blast from the cold blast supply nozzle 124 is stopped with these operations.
Subsequently, as shown in FIG. 12E, the positioning pins 15 a and the stopper 15 b, which are positioning the transport pallet 13, are moved down to release the positioning. After the release, the transport pallet 13 is conveyed in the pallet conveyance direction A by the conveyance unit 14 so that the adjacently arranged next FPC 3 is positioned above the stage 16.
According to the second embodiment, the local cooling of the weak heat-resistant portions can be carried out also by using the cold blast supply nozzle 124 in place of the upper-side heatsink 24 of the weak heat-resistant portion cooling device 22 of the first embodiment, and effects similar to the effects of the first embodiment can be obtained.
Moreover, the arrangement that the local cooling can be carried out without contact with the component 1 with the built-in CCD becomes effective particularly when it is difficult to achieve the contact. For example, it can be considered, for example, a case where the upper surface of the crystal cover section 5 has an undulated configuration or the like.

EXAMPLE

Next, the state of change in the heating temperature of the solder portions 12 and the state of change in the surface temperature of the bonding portions 9 or the CCD 2 when the component 1 with the built-in CCD is mounted (connected) onto the FPC 3 by the electronic component connecting apparatus 101 are shown in FIG. 13.
In this example, the heating conditions of the stage 16 by the heating device 18 include a heating temperature of 350° C. and a heating time of 20 seconds, and the upper-side heatsink 24 of the configuration shown in FIG. 8A and the lower-side heatsink 26 of the configuration shown in FIGS. 3 and 4 are provided. Moreover, the target heating temperature of the solder portions 12 is not lower than 215° C., the temperature upper limit value of the upper surface of the CCD 2 (i.e., the temperature upper limit value of the color filter 10) is not higher than 180° C., and the temperature upper limit value of the bonding portion 6 is not higher than 200° C. By carrying out the aforementioned connection under the conditions of the upper limits, temperature change states as shown in FIG. 13 were able to be detected. In FIG. 13, the vertical axis represents temperature (° C.), the horizontal axis represents time (second), and there are shown the states of change in the temperature of the solder portions 12, the bonding portion 6 and the surface of the CCD 2 (hereinafter assumed to be the color filter 10). Moreover, a time point at which the FPC 3 and the placement surface 16 a of the stage 16 are brought in contact with each other is assumed to be zero second as a reference time.
As shown in FIG. 13, before the zero second of the reference time (i.e., before starting heating), the temperature of the solder portions 12, the bonding portion 6 and the color filter 10 are approximately about 25° C. Subsequently, after the zero second, the heating of the FPC 3 is started, and therefore, the temperatures of the solder portions 12, the bonding portion 6 and the color filter 10 rise. At this time, the placement surfaces 16 a are arranged so as to be adjacent to the respective solder portions 12, and therefore, the temperature of the solder portions 12 can be rapidly raised. On the other hand, by virtue of the lower-side heatsink 26 brought in contact with the neighborhood of the CCD 2, i.e., the neighborhoods of the bonding portion 6 and the color filter 10, the quantity of heat conducted to the bonding portion 6 and the color filter 10 can be partially removed by being conducted to the lower-side heatsink 26. Therefore, the degree of the temperature rise in the bonding portion 6 and the color filter 10 can be restrained in comparison with the temperature rise in the solder portions 12.
Subsequently, at or about the time point of 18 seconds, the temperature of the solder portions 12 exceeds (or reaches) the temperature of 215° C. of the target heating temperature, so that the heat-fusing of the solder portions 12 is started. Subsequently, in an interval of 18 seconds to 20 seconds, the temperature of the solder portions 12 is put in a state in which it is maintained at about 215° C. or higher, so that the solder portions 12 are fused. In the meanwhile, also in this interval, the temperature of the bonding portion 6 is kept not higher than 197° C. and does not exceed 200° C. of the temperature upper limit value. Likewise, in the same interval, the temperature of the color filter 10 is kept not higher than 174° C. and does not exceed 180° C. of the temperature upper limit value.
Subsequently, at the time point of 20 seconds, the contact between the placement surfaces 16 a and the FPC 3 is released, while the contact between the upper-side heatsink 24 and the component 1 with the built-in CCD and the contact between the lower-side heatsink 26 and the FPC 3 are further released, establishing a state in which the heating of the FPC 3 and the cooling of the bonding portion 6 and the cooling color filter 10 concurrent with the heating is stopped. Subsequently, the temperatures of the solder portions 12, the bonding portion 6 and the color filter 10 are lowered, so that the solder portions 12 in the fused state are solidified and the component 1 with the built-in CCD is connected to the FPC 3.
The above-mentioned connection method is able to rapidly heat the solder portions 12 while maintaining the temperatures of the weak heat-resistant portions of the bonding portion 6 and the color filter 10 below the respective upper limit values. Therefore, the occurrence of thermal damage to the weak heat-resistant portions can be prevented, and the time required for the connection can be reduced.
Moreover, the heating temperature profile of the solder portions 12 and the heating temperature profiles of the weak heat-resistant portions of the bonding portion 6 and the color filter 10, as shown in FIG. 13, can be achieved by controlling the time of contact between the stage 16 and the FPC 3, the time of contact between the upper-side heatsink 24 and the component 1 with the built-in CCD and the time of contact between the lower-side heatsink 26 and the FPC 3 by the control unit 90.
(Third Embodiment)
It is to be noted that the present invention is not limited to the aforementioned embodiments but allowed to be embodied in various forms. For example, an electronic component connecting apparatus and method capable of achieving efficient reliable heating when the board placed on the heating stage is heated by heat conduction, will be described below as the third embodiment of the present invention with reference to the drawings. In this case, the electronic component connecting method is the method carried out in the aforementioned electronic component connecting apparatus. It is to be noted that same constituent portions are denoted by same reference numerals in the figures.
In the following embodiments, the electronic components are the components that are to be surface mounted on the circuit board and connected to the circuit board by means of the connection material and correspond to, for example, the chip component 206 and an IC 207 as shown in FIG. 15. As the connection material, solder, i.e., solder paste is taken as an example in terms of workability in the following embodiment. However, the connection material is not limited to this but allowed to be, for example, silver paste, conductive adhesive or the like. Moreover, in the following embodiments, with regard to the circuit board, for example, a film-shaped flexible board, i.e., a FPC (Flexible Printed Circuit Board) is taken as an example of the flexible board that has flexibility. Such the flexible board has features that it easily causes warp, bending and loosening while being held due to the functional characteristic of flexibility possessed, and there are difficulties in securely holding the board. It is to be noted that the board is not limited to the flexible board like this but allowed to be, for example, a board that has a thickness of, for example, not greater than 1 mm or, for example, a thickness within a range of 0.02 mm to 1 mm. Moreover, the presence or absence of flexibility does not matter. In short, the objective boards are not the boards of same type produced in large quantities as in the conventional case but the circuit boards of different types produced in small quantities. Moreover, the circuit board may be a tape-shaped board in which a plurality of flexible boards are continuously formed in a tape-like form. In this case, in may be either a case where boards of identical type are produced in large quantities from the tape-shaped board or a case where boards of different types are produced in small quantities.
FIGS. 14 through 17 show the electronic component connecting apparatus 316 of the present third embodiment. FIG. 15 shows an FPC 205 corresponding to the circuit board to be processed by the electronic component connecting apparatus 316. The FPC 205 is, for example, a board for connecting an LCD module to a mother board and is a single-sided mounting board. A plurality of chip components 206 besides the IC 207 are put (i.e., placed) in portions to which unhardened solder paste 208 is applied on a component mounting surface 205 a of the FPC 205. It is assumed that the IC 207 has been mounted on the FPC 205 before it is carried into the electronic component connecting apparatus 316 in the present embodiment.
The electronic component connecting apparatus 316 is provided with a placement member 305 on which the aforementioned FPC 205 is mounted, a heating stage 306 that heats the FPC 205 put in contact with the placement member 305 by heating the placement member 305 and thereby heat-fuse the solder paste 208 for connecting the electronic components 206 onto the FPC 205 and a pressurizing unit 300 that pressurizes the FPC 205 and the placement member 305 against the heating stage 306.
The placement member 305 has both a function to place and hold the FPC 205 and a function to conduct heat to the FPC 205 and is easily replaceable with respect to the heating stage 306 so as to be able to cope with various types of circuit boards. It is preferable that the placement member 305 has a thickness of about 0.5 mm to 5 mm and is made of a material of good thermal conductivity, such as aluminum, copper, magnesium or ceramic. Particularly, when an aluminum material having a thickness of about 2 mm is employed, the material is preferable since it is low cost and has an intended soaking property. In the present embodiment, the placement member 305 has a square shape of 35 mm×35 mm corresponding to the size of the FPC 205 to be processed. It is to be noted that the term of “soaking property” means the uniformity in the surface temperature distribution of an object, the temperature being changed when heat is applied to the object, and means, for example, a characteristic that has an approximately uniform temperature distribution such that the surface temperature distribution falls within a range of ±5° C.
Further, as shown in FIG. 16 that is the enlarged view of FIG. 14, the pressurizing unit 300 pressurizes the FPC 205 and the placement member 305 against the heating stage 306 with needles 301 provided therefor. A plurality of needles 301 are arranged so as to depress the peripheral portions of the component 304 on the FPC 205 as shown in the figure in the present embodiment, and the number and the positions of the needles 301 are determined in correspondence with the circuit board to be held. For example, it is sometimes a case where the needles are provided in only four places of the peripheral portion of the FPC 205. The needles 301 are fixed on the lower surface of a pressurizing plate 302. Further, by moving down the pressurizing plate 302 by means of an arm 303, it is possible to move down the needles 301 and pressurize the FPC 205. The heating stage 306, which is a heating mechanism, is provided arranged under the placement member 305.
By moving down the arm 303 by a pressurizing mechanism 320, it becomes possible to apply an appropriate pressure capable of reliably pressurizing, the FPC 205 without damaging the FPC 205 and various patterns on the FPC 205 by the needles 301. Moreover, it is acceptable to place a weight in place of the arm 303 on the pressurizing plate 302. When a weight is employed, there are the effects that the mechanism and control becomes simple and the space becomes reduced.
The heating stage 306 is provided with a heating stage 306, a cooling stage 307 and a power supply 310, and the placement member 305 is placed on this heating stage 306.
Moreover, the heating stage 306 is constructed of a so-called ceramic heater and is able to generate heat by supplying a current to the heater wire of the ceramic heater from the power supply 310. In the case of a so-called constant heat heater other than the ceramic heater, it takes tens of seconds to several minutes in terms of response characteristics of temperature rise and fall, and this leads to poor productivity and practicability. However, the ceramic heater is able to respond within one second, and it becomes possible to set a temperature profile as follows. The heating method is not limited to such the heater, and various methods can be adopted.
The temperature of the heating stage 306 is measured by a temperature sensor or, for example, a thermocouple provided in the heating stage 306 and transmitted to a control unit 308. The power supply 310 is connected to the control unit 308, and the control unit 308 controls the temperature of the heating stage 306 in a feedback manner on the basis of temperature information supplied from the thermocouple and the temperature profile preset for temperature control of the circuit board.
Next, the detailed structure of the needle 301 is shown in FIG. 17. The needle 301 is supported by a holder 311 with interposition of an elastic spring 312 together this spring 312. The spring 312 is arranged so as to contract when the tip of the needle 301 is brought in contact with the FPC 205 arranged below the tip and has a function to uniformly adjust the pressurization force for depressing the FPC 205 by the needle 301. Moreover, it is preferable that the spring constant of the spring 112 is selected so as not to damage the FPC 205. It may be a case where an elastic body having another form is employed in place of the spring employed as described above. Moreover, the arrangement of the needles 301 is determined according to the arrangement of the components 304 on the FPC 205. That is, the arrangement of the needles 301 is determined so that the surface of the FPC 205 around the peripheries of the components 304 mounted on the FPC 205 can be depressed. Moreover, the arrangement of the needles 301 is set so as not to come in contact with the solder and bonding material located at the connection portions of the FPC 205 and the components 304.
Moreover, it is preferable to arrange a heat insulating material at the tip portion of each needle 301 or arrange a protection sheet between the two so that the is quantity of heat conducted from the heated FPC 205 to the needles 301 due to the contact between the needles 301 and the FPC 205 can be reduced. Otherwise, it may be a case where a heat insulating material is arranged so that the quantity of heat is not conducted between the needles 301 and the pressurizing plate 302. By reducing the quantity of heat conducted as described above, it becomes possible to reliably efficiently carry out the heating of the FPC 205. As such the heat insulating material, a heat-resistant material of silicone rubber or fluorine-based rubber can be utilized. Particularly, the fluorine-based material has an advantage that it is scarcely contaminated. However, it is required to regularly replace or clean it. It is also acceptable to cover the entire surface of the FPC 205 with a thin sheet-shaped object and pressurize the sheet with the pressurizing unit 300. In this case, by replacing this thin sheet every time or after every prescribed times of use, the problem of cleaning is eliminated. Moreover, if the pressurizing unit 300 is made replaceable and cleaned after replacement, the unit can be repetitively used. The cleaning may be achieved by either a roller type or an ultrasonic cleaning machine. The cleaning may be achieved by a mechanism that is not replaced.
Further, a cooling stage 307 is provided under the heating stage 306 so that the heating stage 306 can be compulsorily cooled to execute temperature control conforming to the temperature profiles shown in FIGS. 18 through 20. A cooling method may be either water cooling or air cooling. Otherwise, it may be a case where the heating stage 306 and the cooling stage 307 are separated from each other during heating so that the cooling stage 307 does not hinder the heating by the heating stage 306 and they are brought in contact with each other during cooling.
The pressuring unit 300, the heating stage 306 and the cooling stage 307 are connected to the control unit 308, and control is carried out by interlinking their operations.
Moreover, with regard to the aforementioned temperature profiles, the temperature profiles as shown in FIGS. 18 through 20 can be considered. The optimum temperature profile is selected in accordance with the parameters of, for example, the type of the connection material, the type and the number of electronic components to be connected onto the circuit board and the material, thickness and so on of the circuit board. As a selection method, there can be adopted any method that can be considered by those skilled in the art, such as a method for preparatorily storing various temperature profiles in correspondence with the parameters in a storage section 309 inside the control unit 308 and inputting information of the circuit board and the electronic components to be processed and automatically extracting the optimum temperature profile by the control unit 308 or inputting the temperature profile selected by the operator.
Moreover, in the graphs of the temperature profiles shown in FIGS. 18 through 20, the vertical axis represents temperature, and the horizontal axis represents time. As for the values in the graphs, according to one example, a0 is the room temperature, al is the fusing point at 183° C. of the connection material since the connection material is eutectic solder in the present embodiment, a2 is 230° C., b1 is 150° C., b2 is 220° C., t1 is one second, t2 is three seconds, t3 is four seconds, t4 is ten seconds and t5 is six seconds.
Particularly, if there are limitations on the heating temperatures of the electronic components 206 and 207, it is proper to assume that the heating temperature to be restricted is a2 and set a heating upper limit temperature b2 lower than a2. Moreover, the FPC 205 is heated from only the back surface 205 b on which no component is mounted, and therefore, the electronic components 206 and 207 are lastly heated. This aspect is also effective when there is restriction of heating.
Moreover, when it is required to restrain the generation of solder balls when the solder is fused, it is appropriate to provide preheating operation to maintain the temperature from time t1 to time t2 as shown in FIG. 18. On the other hand, when the electronic component is comparatively large and the influence of the solder balls can be ignored, it is acceptable to provide no preheating operation and fuse solder at a stroke as shown in FIG. 19. Moreover, if it is desired to reduce the time required for the fusing of solder and the connection of the electronic component to the circuit board, a method for starting the heating preparatorily from the preheating temperature b1 and maintaining the temperature b1 also after the end of the connection with solder, as shown in FIG. 20, is also possible.
The operation of the electronic component connecting apparatus 316 constructed as above, i.e., the electronic component connecting method will be described below. This electronic component connecting method, i.e., the reflow method is a method particularly effective for a circuit board that has a small thickness and suitable for a board that has a thickness of not greater than 1 mm as a reference. Particularly, a film-shaped circuit board, i.e., the FPC 205 has good followability to temperature control and more effective as in the present embodiment. As the material of the circuit board, glass epoxy resin and paper phenol resin are preferable in the case of a circuit board that has a thickness of not greater than 1 mm, and polyimide is preferable for use in the film-shaped circuit board. This is because polyimide has both strength and a heat-resisting property when used for a very thin circuit board that has a thickness of about 0.01 to 0.1 mm.
First of all, the placement member 305, on which the circuit board, i.e., the FPC 205 in this example is placed, is placed on the heating stage 306. Then, the pressurizing unit 300 is operated to depress the placement member 305 against the heating stage 306 via the pressurizing unit 300 and make the placement member 305 closely fit the heating stage 306 for fixation. A pressure for the close-fit fixation of this FPC 205 should preferably be a pressurization force of a degree that the FPC 205 is not damaged. As a result, the placement member 305 closely fits the heating stage 306, and the FPC 205 is held closely fitting the surface of the-placement member 305, so that the heat of the heating stage 306 is efficiently conducted to the FPC 205. The heating operation by the heating stage 306 is controlled by the control unit 308 in accordance with the aforementioned temperature profile, and the solder 208 fuses, so that the electronic component 206 is connected onto the FPC 205 via the solder. After this connection, the operation of the pressurizing unit 300 is stopped to stop the pressurization, and the FPC 205 is unloaded from the placement member 305.
According to the aforementioned electronic component connecting apparatus 316, the circuit board is brought in contact with the placement member 305 that has the same size as that of one circuit board to be heated and heated by the heating stage 306, the generation of loss can be reduced with respect to a small-size circuit board, and heating corresponding to various types of circuit boards can be individually carried out. Therefore, circuit boards of diversified small-lot production can be manufactured with higher productivity than in the conventional case.
Concretely, in contrast to the conventional case where a power of about 20 kW has been needed as unit energy per prescribed amount of circuit boards required for the heating in the conventional reflow furnace, the unit energy can be reduced to about 1 kW in the electronic component connecting apparatus 316 of the third embodiment.
Moreover, the arrangement that the circuit board is brought in contact with the placement member 305 that has the same size as that of one circuit board to be heated and heated by the heating stage 306 obviates the need for the reflow device of the atmosphere circulation type as in the conventional case. Then, in a case where a FPC 205 that has a size of, for example, 35 mm×35 mm is used, each electronic component connecting apparatus 316 can be constructed with a size of, for example, 35 mm×35 mm. Therefore, a heating connection device for a circuit board very compact in comparison with the conventional one can be provided.
Moreover, in the electronic component connecting apparatus 316 of the third embodiment, one FPC 205 is placed on the surface of the placement member 305, and the size of the placement member 305 is equal to or slightly larger than the size of the FPC 205. However, the size of the circuit board corresponding to the placement member 305 is not limited to the example of the third embodiment as described above. For example, in an electronic component connecting apparatus 390 as shown in FIG. 21, it is acceptable to provide two heating stages 306-1 and 306-2 arranged parallel in the sidewise direction and place one circuit board on the placement member 305 arranged on their upper surfaces. Moreover, the direction of parallel arrangement is not limited to the above-mentioned sidewise direction but allowed to be directed in the longitudinal direction or both the sidewise direction and the longitudinal direction. It is also acceptable to arrange a plurality of placement members 305 and place a plurality of FPC's 205 on their surfaces.
With the above-mentioned construction, it becomes possible to adopt the electronic component connecting apparatus 316 of the present embodiment regardless of the size of the circuit board. Moreover, in view of the current situation that there exists comparatively few large-scale ceramic heater and the development cost of the large-scale ceramic heater is huge, the above-mentioned parallel arrangement structure is effective means.
Moreover, by adopting the above-mentioned parallel arrangement structure, it becomes possible to execute one heating control of the whole area in the heating region of one circuit board or execute different heating control operations in a plurality of places in the heating region of one circuit board, acquiring further versatility.
Furthermore, when it is required to more locally change the heating condition of the circuit board, it is possible to provide a construction in which a light beam, laser light or hot air is applied from heat sources 313 arranged on the sides of the FPC 205 as in the electronic component connecting apparatus 391 shown in FIG. 22. In FIGS. 21, 22 and 23, the illustrated power supply 310, pressurizing unit 300, heating stage 306, cooling stage 307 and control unit 308 are similar to those of FIG. 14, and they are partially not shown.
Furthermore, it is acceptable to depress the FPC 205 by a mold 314 in place of the needles in an electronic component connecting apparatus 392 as shown in FIG. 23. With regard to this mold 314, configured portions are formed on its lower surface, and these configured portions are formed in conformity to the pattern of FPC 205, i.e., the arrangement of the components 304, making it possible to depress the upper surface of the FPC 205 on which no component 304 or the like is mounted by the protruding portions of the configured portions. A material of, for example, silicone rubber having a heat insulating property is employed for the portions where the mold 314 and the FPC 205 are brought in contact with each other, so that heat does not escape from the surface of the FPC 205. Moreover, the heat insulating effect can be further improved if the inside of the mold 314 is formed of a hollow in a vacuum, and this arrangement is more preferable. Moreover, it is acceptable to heat the FPC 205 from its upper surface by employing a heater inside the mold 314. In this case, there is a feature that setting of temperatures different between the upper surface and the lower surface of the FPC 205 can be achieved However, it is preferable to provide a path that can let the generated gas component escape.
Furthermore, both the FPC 205 and the components 304 can also be depressed by means of the needles 301 and the pressurizing members 315 in an electronic component connecting apparatus 393 as shown in FIG. 24A. This arrangement is effective for a board of which the component mounting density on the FPC 205 is increased in comparison with the cases of FIGS. 22 and 23. There is no place where each needle 301 directly depresses the FPC 205, and the components 304 are depressed. Moreover, when the component 304 has a poor heat-resisting property, the pressurizing member 315 may be brought in contact with the component in order to deprive the portion of heat. As a connection method of the component that has such a poor heat-resisting property, the connection method described in connection with the first embodiment and the second embodiment can be adopted.
As another modification example, it is possible to employ two types of needles 301-1 and 301-2 of which the lower tips have mutually different height positions, depress the surface where no component 304 is arranged on the FPC 205 by means of the needles 301-1 and depress the components 304 by means of the needles 301-2 in an electronic component connecting apparatus 394 as shown in FIG. 24B. In this case, the arrangement and the heights of the needles 301-1 and needles 301-2 are required to be adjusted to the arrangement of the components 304 mounted on the FPC 205. In accordance with an increase in the mounting density of the components 304 and the like on the FPC 205, this kind of method is effective.
(Fourth Embodiment)
An electronic component mounting apparatus (also referred to as a “mounting system”) employing an electronic component connecting apparatus 490 that has the construction and the function of the electronic component connecting apparatus 316 of the third embodiment will be described next as an electronic component mounting apparatus according to the fourth embodiment of the present invention. A schematic view showing the construction of the mounting system 401 of the present fourth embodiment is shown in FIG. 26. It is to be noted that the FPC 205 is taken as one example of the circuit board.
As shown in FIG. 26, the mounting system 401 is provided with a solder feeding apparatus 410 for applying the solder paste 208 to the FPC 205, a component placing apparatus 420 that is one example of the electronic component placing apparatus for placing the chip components 206 on the FPC 205 and an electronic component connecting apparatus 490 for fusing the solder paste 208 and connecting the chip components 206 to the FPC 205, which are arranged so that each FPC 205 is conveyed to the solder feeding apparatus 410, the component placing apparatus 420 and the electronic component connecting apparatus 490 in this order. It is to be noted that each FPC 205 on which the IC 207 has been preparatorily mounted is fed to the solder feeding apparatus 410. The solder feeding apparatus 410 may have a construction of either a solder printer or a solder dispenser.
Moreover, as described in connection with the electronic component connecting apparatus 316 of the third embodiment, the electronic component connecting apparatus 490 that has approximately similar construction and functions is constructed so as to pressurize the board on the placement member and carry out heating in the pressurized state. Furthermore, the size of one placement member corresponds to the size of the board, and therefore, the area occupied by the electronic component connecting apparatus 490 becomes significantly smaller than the conventional reflow apparatus. Therefore, the total length I of the mounting system 401 can be reduced to about 2.5 m in the case of the present example.
A schematic view showing the construction of the electronic component connecting apparatus 490 provided for the mounting system 401 is shown in FIG. 25, and the electronic component connecting apparatus 490 will be described with reference to FIG. 25.
As shown in FIG. 25, the electronic component connecting apparatus 490 is provided with a heating section 435, a conveyance unit 431 for conveying the FPC 205 from the component placing apparatus 420 arranged adjacently on the upstream side (preceding process side) of the mounting system 401 into the electronic component connecting apparatus 490, a conveyance unit 433 for conveying the FPC 205 from the electronic component connecting apparatus 490 toward the downstream side (subsequent process side) of the mounting system 401, a conveyance unit 432 for conveying the FPC 205 from the conveyance unit 431 to the heating section 435 and from the heating section 435 to the conveyance unit 433 and a control unit 436 for executing operation control of these constituent sections.
The conveyance unit 431 is provided with a conveyance base 4312 that sucks and holds the FPC 205 and-reciprocates in the illustrated X-axis direction of the conveyance direction by a drive unit 4311, and the operation of the conveyance unit 431 is controlled by the control unit 436. The conveyance unit 433 is provided with a conveyance base 4332 that sucks and holds the FPC 205 and reciprocates in the illustrated X-axis direction by a drive unit 4331, and the operation of the conveyance unit 433 is controlled by the control unit 436.
The heating section 435 is constructed of two stages of a first stage 435-1 and a second stage 435-2, and the first stage 435-1 and the second stage 435-2 are each constructed of two electronic component connecting apparatuses 316 of the third embodiment shown in FIG. 14 arranged in the longitudinal direction, i.e., in the Y-axis direction shown in FIG. 25. Therefore, a total of four electronic component connecting apparatuses 316 are employed in the heating section 435. This is because one FPC 205 to be processed by the mounting system 401 has a size corresponding to the size of two placement members 305 of the electronic component connecting apparatuses 316 arranged in the Y-axis direction. It is to be noted that the concrete size of the FPC 205 to be processed by the mounting system 401 is, for example, 35 mm×70 mm. As described above, the size of the stage is not limited to the form of the mounting system 401, and it is proper to determine the size in accordance with the size of the circuit board to be processed. Moreover, the number of the stages to be provided in the heating section 435 is also not limited to the present example but required to be at least one, and the number is determined on the basis of the processing performance required for the mounting system.
Moreover, a power supply, a pressurizing unit, a pressurizing mechanism and a cooling stage provided for each of the electronic component connecting apparatuses that constitute the stages 435-1 and 435-2 are not shown in FIG. 25 since they can be understood similarly to FIG. 14. Moreover, temperature control similar to the temperature control described in connection with the third embodiment can be executed by the operation control of the control unit 436 with regard to each of the first stage 435-1 and the second stage 435-2.
The conveyance unit 432 is provided with a conveyance suction unit 4321 that conveys the FPC 205 from the conveyance base 4312 of the conveyance unit 431 to the first stage 435-1 and the second stage 435-2 of the heating section 435, a conveyance suction unit 4322 that conveys the FPC 205 from the first stage 435-1 and the second stage 435-2 to the conveyance base 4332 of the conveyance unit 433, a Z-axis drive unit 4324 that moves a conveyance arm 4323 to which the conveyance suction unit 4321 and the conveyance suction unit 4322 are fixed in a Z-axis direction that is the direction of thickness of the FPC 205 and is perpendicular to the X-axis direction and the Y-axis direction, a Y-axis drive unit 4325 that moves the Z-axis drive unit 4324 in the Y-axis direction and an X-axis drive unit 4326 that moves the Y-axis drive unit 4325 in the X-axis direction. The conveyance suction unit 4321 and the conveyance suction unit 4322 are each provided with a suction device (not shown). The conveyance unit 432, which has the above-mentioned construction, has its operation controlled by the control unit 436.
Further, the electronic component connecting apparatus 490 is provided with a suction unit 434 that has a duct 4341 for sucking fume generated from the FPC 205 being heated by the heating section 435.
Operation of the mounting system 401 that has the aforementioned construction will be described below mainly about the operation of the electronic component connecting apparatus 490.
In the mounting system 401, the FPC 205 conveyed from the component placing apparatus 420 is fed onto the conveyance base 4312 of the conveyance unit 431 provided for the electronic component connecting apparatus 490. The X-axis drive unit 4326, the Y-axis drive unit 4325, the Z-axis drive unit 4324 and the conveyance suction unit 4321, which are provided for the conveyance unit 432, are each driven, by which the FPC 205 is sucked and held by the conveyance suction unit 4321 and sucked and held while being placed on the first stage 435-1 of the heating section 435. Then, the FPC 205 is subjected to heating, i.e., reflow operation by the heating stage 306 while being retained on the first stage 435-1 on the basis of the aforementioned temperature profile. The fume generated during this heating is sucked by the duct 4341 of the suction unit 434.
Next, the second FPC 205 carried into the electronic component connecting apparatus 490 is also handled similarly to the first FPC 205. This second FPC 205 is fed to the second stage 435-2 that is currently unoccupied and subjected to heating and control in temperature for the connection of the FPC 205 and the chip components 206. Further, the next third FPC 205 is preparatorily sucked by the conveyance suction unit 431 and immediately fed to the first stage 435-1 after the heating of the first FPC 205 conveyed first on the first stage 435-1 ends and unloaded from the first stage 435-1 to the conveyance base 4332 of the conveyance unit 433 by the conveyance suction unit 4322 of the conveyance unit 432.
The FPC 205, which is placed on and sucked by the conveyance base 4332, is held and conveyed to the next process. By repeating the above-mentioned operation, the FPC's 205 are successively processed.
According to the mounting system 401 provided with the electronic component connecting apparatus 490, the electronic component connecting apparatus 490 is constructed more compactly than in the conventional case, and therefore, the total scale of the mounting system 401 can be made more compact than in the conventional case.
Moreover, as shown in FIG. 26, the aforementioned mounting system 401 has the construction in which the solder feeding apparatus 410, the component placing apparatus 420 and the electronic component connecting apparatus 490 are arranged in a line along the board conveyance direction, i.e., the X-axis direction. However, the overall construction of the mounting system is not limited to the above-mentioned construction, and it is acceptable to constitute, for example, a rotary type mounting system 450 as shown in FIG. 27.
As shown in FIG. 27, the mounting system 450 is provided with a solder feeding apparatus 461 in which a circular rotary table 457 of which the peripheral portion is provided with working sections 458 arranged at regular intervals is intermittently rotatably provided in the center portion of the mounting system 450 and which surrounds the rotary table 457 and feeds solder to the board in correspondence with the stop position of the working sections 458, a component placing apparatus 462 that places chip components 206 on the board fed with solder, and an electronic component connecting apparatus 463 that connects the chip components 206 to the board by heating the solder. Further, a control unit 456 that manages operation control of the whole mounting system 450 is further provided. There are further provided a conveyance unit 451 for conveying a board from the preceding process to the mounting system 450, a conveyance unit 453 for conveying a board from the mounting system 450 to the next process and a conveyance unit 452 for conveying a board to the working section 458. There is further provided a suction device for sucking the fume generated during the heating of the board.
The mounting system 450 constructed as above operates as follows.
In the mounting system 450 shown in FIG. 27, a board is placed in the working section 458 by the conveyance unit 452 via the conveyance unit 451 and conveyed to the solder feeding apparatus 461 by the rotation of the rotary table 457. In the solder feeding apparatus 461, solder is fed to the board. Then, the rotary table 457 rotates again, and the board is conveyed to the component placing apparatus 462. In the component placing apparatus 462, each chip component 206 is placed on the board fed with solder. Then, the rotary table 457 rotates again to convey the board to the electronic component connecting apparatus 463. In the electronic component connecting apparatus 463, heating of the board and connection of the component to the board are carried out. Subsequently, the board is placed on the conveyance unit 453 by the conveyance unit 452, and the conveyance unit 453 conveys the board to the next process.
For example, when the first board is heated by the electronic component connecting apparatus 463, components are placed on the second board by the component placing apparatus 462, and solder is fed to the third board by the solder feeding apparatus 461. As described above, different processes are concurrently carried out for a plurality of boards in the mounting system 450.
Further, as in the mounting system 450, the width of the mounting system 450 can be further reduced by adopting the form provided with the rotary table 457.
Moreover, if the stop position of the rotary table 457 is divided into eight positions, it is possible to further provide a recognition camera for inspecting the state of feed of solder to the board and a device for adding solder to the portions fed with insufficient solder between the solder feeding apparatus 461 and the component placing apparatus 462 and to effectively utilize them. Moreover, the electronic component connecting apparatus 463 can also be provided inside the working section 458, at the conveyance unit 453 or between the rotary table 457 and the conveyance unit 453.
It is to be noted that, by properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by them can be produced.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
The disclosure of Japanese Patent Application No.2003-275941 filed on Jul. 17, 2003 and No.2004-031778 filed on Feb. 9, 2004 including specification, drawing and claims are incorporated herein by reference in its entirety.

Claims

1. A component connecting apparatus comprising:

a placement member on which a board is placed, the board receiving thereon a component that has a connection portion to be connected to an electrode of the board and a weak heat-resistant portion of a heatproof temperature lower than a fusing point of a connection material for connecting the electrode of the board and the connection portion to each other with interposition of the connection material between the electrode of the board and the connection portion;

a heating device for fusing the connection material by heating the placement member to heat the board brought in contact with the placement member; and

a weak heat-resistant portion cooling device for cooling the weak heat-resistant portion or its neighborhood so as to prevent thermal damage to the weak heat-resistant portion by reducing a quantity of heat conducted from the heating device to the weak heat-resistant portion via the board, whereby

the component is connected to the board which is placed on the placement member with interposition of the connection material by fusing the connection material by the heating device while carrying out the cooling by the weak heat-resistant portion cooling device and solidifying the fused connection material.

2. The component connecting apparatus as claimed in claim 1, wherein the weak heat-resistant portion cooling device comprises a cooling member for carrying out the cooling by coming in contact with the weak heat-resistant portion or its neighborhood, thereby conducting the quantity of heat from the component.

3. The component connecting apparatus as claimed in claim 2, wherein the cooling by the cooling member is carried out so that a temperature of the weak heat-resistant portion becomes equal to or lower than its heatproof temperature when the connection material is fused by the heating device.

4. The component connecting apparatus as claimed in claim 2, wherein the weak heat-resistant portion is arranged inside the component, and the cooling member is brought in indirect contact with the weak heat-resistant portion via the neighborhood of the weak heat-resistant portion.

5. The component connecting apparatus as claimed in claim 2, wherein the cooling member is brought in indirect contact with the weak heat-resistant portion via the board.

6. The component connecting apparatus as claimed in claim 2, wherein the placement member has a placement surface which is brought in contact with a part of the board in a neighborhood of a position in which the electrode of the board is formed and on which the board is placed.

7. The component connecting apparatus as claimed in claim 2, further comprising a suction device which is connected to the placement member and makes the placement member suck and hold the board.

8. The component connecting apparatus as claimed in claim 2, wherein the cooling member has a cooling fluid passage for making a cooling fluid pass through its inside, and the quantity of heat conducted from the component to the cooling member can be removed by making the cooling fluid pass through the cooling fluid passage.

9. The component connecting apparatus as claimed in claim 2, wherein the weak heat-resistant portion cooling device further comprises a cooling member moving unit for moving the cooling member between a position of contact of the cooling member and a position in which the contact can be released.

10. The component connecting apparatus as claimed in claim 9, wherein the weak heat-resistant portion cooling device has the cooling member opposite to the placement member, and by positioning the cooling member in the position of contact by the cooling member moving unit, a position where the board is mounted is placed on the placement member is retained.

11. The component connecting apparatus as claimed in claim 2, wherein the cooling member is formed of a material whose thermal conductivity is higher than thermal conductivity of a formation material of the component.

12. The component connecting apparatus as claimed in claim 2, further comprising a control unit for controlling a temperature of the placement member at a constant temperature by the heating device, and the control unit controls a heating temperature profile of the connection material and a temperature profile of the weak heat-resistant portion by controlling a time of contact between the placement member whose temperature is controlled at the constant temperature and the board and a time of contact between the cooling member and the component.

13. The component connecting apparatus as claimed in claim 1, wherein the heating device has a heating member for heating the placement member, and

the component connecting apparatus further comprises a pressurizing unit for pressurizing the board against the heating member so as to make the board closely fit the placement member and make the placement member closely fit the heating member.

14. The component connecting apparatus as claimed in claim 13, wherein the pressurizing unit comprises a plurality of protruding portions or configured portions, and the board is pressurized against the heating member via the protruding portions or the configured portions.

15. A component mounting apparatus comprising:

a component placing apparatus for placing the component on the board with interposition of the connection material; and

the component connecting apparatus claimed in claim 2, for connecting the component which has been placed on the board by the component placing apparatus to the board.

16. A component connecting method comprising:

placing a board on a placement member, the board receiving thereon a component that has a connection portion to be connected to an electrode of the board and a weak heat-resistant portion of a heatproof temperature lower than a fusing point of a connection material for connecting the electrode of the board and the connection portion to each other with interposition of the connection material between the electrode of the board and the connection portion;

bringing a cooling member in contact with the weak heat-resistant portion or its neighborhood while heating the connection material by heating the board brought in contact with the placement member, reducing a quantity of heat conducted to the weak heat-resistant portion via the board by conducting the quantity of heat to the cooling member and fusing the connection material while maintaining a temperature of the weak heat-resistant portion at or below its heatproof temperature; and

connecting the component to the board with interposition of the connection material by subsequently solidifying the connection material.

17. The component connecting method as claimed in claim 16, wherein the weak heat-resistant portion is arranged inside the component, and the cooling member is brought in indirect contact with the weak heat-resistant portion via the neighborhood of the weak heat-resistant portion.

18. The component connecting method as claimed in claim 16, wherein temperature rise in the weak heat-resistant portion is restrained so that the temperature of the weak heat-resistant portion becomes equal to or lower than the heatproof temperature by a time when a temperature of the connection material is maintained at a temperature not lower than its fusing point by heating of the board and the fusing of the connection material is completed.

19. The component connecting method as claimed in claim 16, wherein the placement member is maintained at a constant heating temperature, and by controlling a time of contact between the placement member and the board and a time of contact between the cooling member and the component, a heating temperature profile of the connection material and a temperature profile of the weak heat-resistant portion are controlled.

20. The component connecting method as claimed in claim 16, wherein the board placed on the placement member is pressurized against the placement member to make the board closely fit the placement member, and the board is heated via the placement member.